3 - EXPANDING-TYPE SNAP-RING PLIERS 4 - CLUTCH DRUM 5 - ANNULUS GEAR 6 - OVERRUNNING CLUTCH ASSEMBLY SEATED IN OUTPUT SHAFT
21 - 230
OVERDRIVE UNIT (Continued)
AUTOMATIC TRANSMISSION - 46RE
(11) Install planetary gear in annulus gear (Fig. 173). Be sure planetary pinions are fully seated in annulus gear before proceeding.
DR
Fig.175SunGearInstallation
1 - SUN GEAR AND SPRING PLATE ASSEMBLY
(15) Mount assembled output shaft, annulus gear, and clutch drum in shop press. Direct clutch spring, hub and clutch pack are easier to install with assem- bly mounted in press.
(16) Align splines in hubs of planetary gear and overrunning clutch with Alignment tool 6227-2 (Fig. 176). Insert tool through sun gear and into splines of both hubs. Be sure alignment tool is fully seated before proceeding.
Fig.173PlanetaryGearInstallation
1 - PLANETARY GEAR 2 - ANNULUS GEAR
(12) Coat planetary thrust bearing and bearing contact surface of spring plate with generous amount of petroleum jelly. This will help hold bearing in place during installation.
(13) Install planetary thrust bearing on sun gear (Fig. 174). Slide bearing onto gear and seat it against spring plate as shown. Bearing fits one way only. If it does not seat squarely against spring plate, remove and reposition bearing.
(14) Install assembled sun gear, spring plate and thrust bearing (Fig. 175). Be sure sun gear and thrust bearing are fully seated before proceeding.
Fig.174PlanetaryThrustBearingInstallation
Fig.176AlignmentToolInstallation
1 - SPRING PLATE 2 - PLANETARY THRUST BEARING 3 - SUN GEAR
1 - SPECIAL TOOL 6227-2
2 - PRESS PLATES
3 - ASSEMBLED DRUM AND ANNULUS GEAR
4 - SUN GEAR
DR OVERDRIVE UNIT (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 231
(17) Install direct clutch spring (Fig. 177). Be sure
spring is properly seated on spring plate.
Splines at rear of hub are raised slightly. Counter- bore in plate fits over raised splines. Plate should be flush with this end of hub (Fig. 179).
Fig.177DirectClutchSpringInstallation
1 - SPECIAL TOOL 6227-2
2 - DIRECT CLUTCH SPRING
3 - CLUTCH HUB
4 - PRESS PLATES
NOTE: The direct clutch in a 46RE transmission uses 8 clutch discs.
(18) Assemble and install direct clutch pack on
hub as follows:
(a) Assemble clutch pack components (Fig. 178). (b) Install direct clutch reaction plate on clutch hub first. Note that one side of reaction plate is counterbored. Be sure this side faces rearward.
Fig.179CorrectPositionOfDirectClutchReaction
Plate
1 - REACTION PLATE COUNTERBORE 2 - DIRECT CLUTCH REACTION PLATE (FLUSH WITH END OF HUB) 3 - CLUTCH HUB
1 - CLUTCH DISCS (8) 2 - PRESSURE PLATE
3 - CLUTCH PLATES (7) 4 - REACTION PLATE
Fig.17846REDirectClutchPackComponents
21 - 232
OVERDRIVE UNIT (Continued)
AUTOMATIC TRANSMISSION - 46RE
(c) Install first clutch disc followed by a steel plate until all discs and plates have been installed. (d) Install pressure plate. This is last clutch pack item to be installed. Be sure plate is installed with shoulder side facing upward (Fig. 180). (19) Install clutch hub and clutch pack on direct clutch spring (Fig. 181). Be sure hub is started on sun gear splines before proceeding.
DR
WARNING: THE NEXT STEP IN GEARTRAIN ASSEM-
BLY INVOLVES COMPRESSING THE DIRECT CLUTCH
HUB AND SPRING.
IT IS EXTREMELY IMPORTANT
THAT PROPER EQUIPMENT BE USED TO COMPRESS
THE SPRING AS SPRING FORCE IS APPROXIMATELY
830 POUNDS. USE COMPRESSOR TOOL C-6227-1
AND A HYDRAULIC-TYPE SHOP PRESS WITH A MINI-
MUM RAM TRAVEL OF 6 INCHES. THE PRESS MUST
ALSO HAVE A BED THAT CAN BE ADJUSTED UP OR
DOWN AS REQUIRED. RELEASE CLUTCH SPRING
TENSION SLOWLY AND COMPLETELY TO AVOID PER-
SONAL INJURY.
(20) Position Compressor Tool 6227-1 on clutch
hub.
(21) Compress clutch hub and spring just enough
to place tension on hub and hold it in place.
(22) Slowly compress clutch hub and spring. Com- press spring and hub only enough to expose ring grooves for clutch pack snap ring and clutch hub retaining ring.
(23) Realign clutch pack on hub and seat clutch
discs and plates in clutch drum.
(24) Install direct clutch pack snap ring (Fig. 182). Be very sure snap ring is fully seated in clutch drum ring groove.
(25) Install clutch hub retaining ring (Fig. 183). Be very sure retaining ring is fully seated in sun gear ring groove.
(26) Slowly release press ram, remove compressor
tools and remove geartrain assembly.
Fig.180CorrectPositionOfDirectClutch
1 - DIRECT CLUTCH PRESSURE PLATE 2 - CLUTCH PACK 3 - BE SURE SHOULDER SIDE OF PLATE FACES UPWARD
Fig.181DirectClutchPackAndClutchHub
Installation
1 - CLUTCH HUB 2 - DIRECT CLUTCH PACK 3 - CLUTCH DRUM
Fig.182DirectClutchPackSnap-RingInstallation
1 - SPECIAL TOOL 6227-1
2 - DIRECT CLUTCH PACK SNAP-RING
GEAR CASE
(1) Position park pawl and spring in case and install park pawl shaft. Verify that end of spring with 90° bend is hooked to pawl and straight end of spring is seated against case.
DR OVERDRIVE UNIT (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 233
Fig.183ClutchHubRetainingRingInstallation
1 - SPECIAL TOOL 6227-1
2 - CLUTCH HUB RETAINING RING
Fig.185ReactionPlugAndSnap-RingInstallation 1 - REACTION PLUG SNAP-RING 2 - SNAP-RING PLIERS
(2) Install pawl shaft retaining bolt. Tighten bolt
to 27 N·m (20 ft. lbs.) torque.
(3) Install park lock reaction plug. Note that plug has locating pin at rear (Fig. 184). Be sure pin is seated in hole in case before installing snap ring.
(4) Install reaction plug snap-ring (Fig. 185). Com- press snap ring only enough for installation; do not distort it.
(5) Install new seal
in gear case. Use Handle
C-4171 and Installer C-3995-A to seat seal in case.
(6) Verify that tab ends of rear bearing locating ring extend into access hole in gear case (Fig. 186).
Fig.184ReactionPlugLocatingPinAndSnap-Ring 1 - REACTION PLUG SNAP-RING (DO NOT OVERCOMPRESS TO INSTALL) 2 - LOCATING PIN 3 - PARK LOCK REACTION PLUG
Fig.186CorrectRearBearingLocatingRing
Position
1 - CASE ACCESS HOLE 2 - TAB ENDS OF LOCATING RING
21 - 234
OVERDRIVE UNIT (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(7) Support geartrain on Tool 6227-1 (Fig. 187). Be
sure tool is securely seated in clutch hub.
(8) Install overdrive gear case on geartrain (Fig.
187).
Fig.189LocatingRingAccessCoverAndGasket
Installation
1 - TORX SCREWDRIVER (T25) 2 - ACCESS COVER SCREWS
(1) Install overdrive clutch reaction ring first.
Reaction ring is flat with notched ends (Fig. 190).
(2) Install wave spring on top of reaction ring (Fig. 191). Reaction ring and wave ring both fit in same ring groove. Use screwdriver to seat each ring securely in groove. Also ensure that the ends of the two rings are offset from each other.
Fig.187OverdriveGearCaseInstallation
1 - GEARTRAIN ASSEMBLY 2 - GEAR CASE
(9) Expand front bearing locating ring with snap ring pliers (Fig. 188). Then slide case downward until locating ring locks in bearing groove and release snap ring.
(10) Install locating ring access cover and gasket
in overdrive unit case (Fig. 189).
Fig.190OverdriveClutchReactionRingInstallation 1 - REACTION RING 2 - CLUTCH HUB
Fig.188SeatingLocatingRingInRearBearing
1 - EXPAND BEARING LOCATING RING WITH SNAP-RING PLIERS 2 - ACCESS HOLE
OVERDRIVE CLUTCH
NOTE: The overdrive clutch in a 46RE transmission uses 4 clutch discs.
Fig.191OverdriveClutchWaveSpringInstallation 1 - WAVE SPRING
AUTOMATIC TRANSMISSION - 46RE
21 - 235
output shaft is not loaded and internal components are moved rearward for accurate measurement.
(2) Determine correct thickness intermediate shaft
spacer as follows:
(a) Insert Special Tool 6312 through sun gear, planetary gear and into pilot bushing in output shaft. Be sure tool bottoms against planetary shoulder.
(b) Position Gauge Tool 6311 across face of over- drive case (Fig. 194). Then position Dial Caliper C-4962 over gauge tool.
(c) Extend sliding scale of dial caliper downward through gauge tool slot until scale contacts end of Gauge Alignment Tool 6312. Lock scale in place. Remove dial caliper tool and note distance mea- sured (Fig. 194).
(d) Select proper thickness end play spacer from spacer chart based on distance measured (Fig. 195).
(e) Remove Gauge Alignment Tool 6312.
DR OVERDRIVE UNIT (Continued)
(3) Assemble overdrive clutch pack (Fig. 192).
Fig.19246REOverdriveClutchComponents
1 - REACTION PLATE 2 - CLUTCH PLATES (3)
3 - PRESSURE PLATE 4 - CLUTCH DISCS (4)
(4) Install overdrive clutch reaction plate first.
NOTE: The reaction plate is the same thickness as the pressure plate in a 46RE transmission.
(5) Install first clutch disc followed by first clutch plate. Then install remaining clutch discs and plates in same order.
(6) Install clutch pack pressure plate. (7) Install clutch pack wire-type retaining ring
(Fig. 193).
Fig.194ShaftEndPlayMeasurement
1 - SPECIAL TOOL 6312
2 - SPECIAL TOOL 6311
3 - SPECIAL TOOL C-4962
Fig.193OverdriveClutchPackRetainingRing
Installation
1 - OVERDRIVE CLUTCH PACK RETAINING RING
INTERMEDIATE SHAFT SPACER SELECTION
(1) Place overdrive unit in vertical position. Mount it on blocks, or in workbench with appropriate size mounting hole cut into it. Be sure unit is facing upward for access to direct clutch hub. Also be sure
Fig.195IntermediateShaftEndPlaySpacer
Selection
AUTOMATIC TRANSMISSION - 46RE
21 - 236
OVERDRIVE UNIT (Continued)
OD THRUST PLATE SELECTION
DR
(1) Place overdrive unit in vertical position. Mount it on blocks, or in workbench with appropriate size mounting hole cut into it. Be sure unit is facing upward for access to direct clutch hub. Also be sure output shaft is not loaded and internal components are moved rearward for accurate measurement.
(2) Determine correct thickness overdrive piston
thrust plate as follows:
(a) Position Gauge Tool 6311 across face of over- drive case. Then position Dial Caliper C-4962 over gauge tool (Fig. 196).
(b) Measure distance to clutch hub thrust bear- ing seat at four points 90° apart. Then average measurements by adding them and dividing by 4. (c) Select and install required thrust plate from
information in thrust plate chart (Fig. 197). (3) Leave Alignment Tool 6227-2 in place. Tool will keep planetary and clutch hub splines in alignment until overdrive unit is ready for installation on trans- mission.
(4) Transmission speed sensor can be installed at this time if desired. However, it is recommended that sensor not be installed until after overdrive unit is secured to transmission.
Fig.197OverdrivePistonThrustPlateSelection
(a) Aligning locating lugs on overdrive piston to
the two mating holes in retainer.
(b) Lubricate overdrive piston seals with Mopart
Door Ease, or equivalent.
(c) Install piston over Seal Guide 8114–3 and
inside Guide Ring 8114–1.
(d) Push overdrive piston into position in
(e) Verify that the locating lugs entered the lug
bores in the retainer. (6) Install intermediate shaft spacer on intermedi-
(7) Install overdrive piston thrust plate on over-
(8) Install overdrive piston thrust bearing on over-
(9) Install transmission speed sensor and O-ring
retainer.
ate shaft.
drive piston.
drive piston.
seal in overdrive case.
INSTALLATION
Fig.196OverdrivePistonThrustPlateMeasurement
1 - SPECIAL TOOL 6311
2 - DIRECT CLUTCH HUB THRUST BEARING SEAT
3 - SPECIAL TOOL C-4962
OVERDRIVE PISTON
(1) Install new seals on overdrive piston. (2) Stand transmission case upright on bellhous-
ing.
(3) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
overdrive piston retainer.
(4) Position Seal Guide 8114-3 on inner edge of
(5) Install overdrive piston in overdrive piston
retainer by:
(1) Be sure overdrive unit Alignment Tool 6227-2
is fully seated before moving unit. If tool
is not
seated and gear splines rotate out of alignment, over-
drive unit will have to be disassembled in order to
realign splines.
(2) If overdrive piston retainer was not removed during service and original case gasket is no longer reusable, prepare new gasket by trimming it.
(3) Cut out old case gasket around piston retainer
with razor knife (Fig. 198).
(4) Use old gasket as template and trim new gas-
ket to fit.
(5) Position new gasket over piston retainer and on transmission case. Use petroleum jelly to hold gasket in place if necessary. Do not use any type of sealer to secure gasket. Use petroleum jelly only.
(6) Install selective spacer on intermediate shaft, if removed. Spacer goes in groove just rearward of shaft rear splines (Fig. 199).
DR OVERDRIVE UNIT (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 237
rotate out of alignment. If this occurs, it will be nec- essary to remove and disassemble overdrive unit to realign splines.
(11) Work overdrive unit forward on intermediate
shaft until seated against transmission case.
(12) Install bolts attaching overdrive unit to trans-
mission unit. Tighten bolts in diagonal pattern to 34
N·m (25 ft-lbs).
(13) Connect the transmission speed sensor and
overdrive wiring connectors.
(14) Install the transfer case, if equipped. (15) Align and install rear propeller shaft, if nec- essary. (Refer to 3 - DIFFERENTIAL & DRIVELINE/ PROPELLER INSTALLATION)
SHAFT/PROPELLER
SHAFT
Fig.198TrimmingOverdriveCaseGasket
1 - GASKET 2 - SHARP KNIFE
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER DESCRIPTION
The overrunning clutch (Fig. 200) consists of an inner race, an outer race (or cam), rollers and springs, and the spring retainer. The number of roll- ers and springs depends on what transmission and which overrunning clutch is being dealt with.
Fig.199IntermediateShaftSelectiveSpacer
Location
1 - SELECTIVE SPACER 2 - SPACER GROOVE 3 - INTERMEDIATE SHAFT
(7) Install thrust bearing in overdrive unit sliding hub. Use petroleum jelly to hold bearing in position.
CAUTION: Be sure the shoulder on the inside diam- eter of the bearing is facing forward.
(8) Verify that splines in overdrive planetary gear and overrunning clutch hub are aligned with Align- ment Tool 6227-2. Overdrive unit cannot be installed if splines are not aligned. If splines have rotated out of alignment, unit will have to be disassembled to realign splines.
(9) Carefully slide Alignment Tool 6227-2 out of overdrive planetary gear and overrunning clutch splines.
(10) Raise overdrive unit and carefully slide it straight onto intermediate shaft. Insert park rod into park lock reaction plug at same time. Avoid tilting overdrive during installation as this could cause planetary gear and overrunning clutch splines to
Fig.200OverrunningClutch
1 - OUTER RACE (CAM) 2 - ROLLER 3 - SPRING 4 - SPRING RETAINER 5 - INNER RACE (HUB)
OPERATION
As the inner race is rotated in a clockwise direction (as viewed from the front of the transmission), the race causes the rollers to roll toward the springs, causing them to compress against their retainer. The compression of the springs increases the clearance
21 - 238
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
between the rollers and cam. This increased clear- ance between the rollers and cam results in a free- wheeling condition. When the inner race attempts to rotate counterclockwise, the action causes the rollers to roll in the same direction as the race, aided by the pushing of the springs. As the rollers try to move in the same direction as the inner race, they are wedged between the inner and outer races due to the design of the cam. In this condition, the clutch is locked and acts as one unit.
DISASSEMBLY
(1) Remove the overdrive piston (Fig. 201). (2) Remove the overdrive piston retainer bolts. (3) Remove overdrive piston retainer. (4) Remove case gasket. (5) Tap old cam out of case with pin punch. Insert punch through bolt holes at rear of case (Fig. 202). Alternate position of punch to avoid cocking cam dur- ing removal.
(6) Clean clutch cam bore and case. Be sure to remove all chips/shavings generated during cam removal.
Fig.201OverdrivePistonRemoval
1 - OVERDRIVE CLUTCH PISTON 2 - INTERMEDIATE SHAFT 3 - SELECTIVE SPACER 4 - PISTON RETAINER
Fig.202OverrunningClutchCam
1 - PIN PUNCH 2 - REAR SUPPORT BOLT HOLES
CLEANING
Clean the overrunning clutch assembly, clutch cam, low-reverse drum, and overdrive piston retainer in solvent. Dry them with compressed air after clean- ing.
INSPECTION
Inspect condition of each clutch part after cleaning. Replace the overrunning clutch roller and spring assembly if any rollers or springs are worn or dam- aged, or if the roller cage is distorted, or damaged. Replace the cam if worn, cracked or damaged.
Replace the low-reverse drum if the clutch race, roller surface or inside diameter is scored, worn or damaged. Do not remove the clutch race from the low-reverse drum under any circumstances. Replace the drum and race as an assembly if either component is damaged.
Examine the overdrive piston retainer carefully for wear, cracks, scoring or other damage. Be sure the retainer hub is a snug fit in the case and drum. Replace the retainer if worn or damaged.
DR OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued) ASSEMBLY
AUTOMATIC TRANSMISSION - 46RE
21 - 239
(1) Temporarily install overdrive piston retainer in
case. Use 3-4 bolts to secure retainer.
(2) Align and start new clutch cam in the trans- mission case. Be sure serrations on cam and in case are aligned (Fig. 203). Then tap cam into case just enough to hold it in place.
(3) Verify that cam is correctly positioned before proceeding any further. Narrow ends of cam ramps should be to left when cam is viewed from front end of case (Fig. 203).
(4) Insert Adapter Tool SP-5124 into piston
retainer (Fig. 204).
SP-3583-A (Fig. 205).
(5) Assemble Puller Bolt SP-3701 and Press Plate
Fig.205AssemblingClutchCamPullerBoltAnd
PressPlate
1 - PULLER BOLT SP-3701
2 - PRESS PLATE SP-3583-A
(6) Install assembled puller plate and bolt (Fig. 206). Insert bolt through cam, case and adapter tool. Be sure plate is seated squarely on cam.
Fig.203PositioningReplacementClutchCamIn
Case
1 - ALIGN SERRATIONS ON CAM AND IN CASE 2 - CLUTCH CAM
Fig.206PositioningPullerPlateOnClutchCam
1 - SPECIAL TOOL SP-3701
2 - BE SURE PLATE SP-3583-A IS SEATED SQUARELY ON CAM
Fig.204PositioningAdapterToolInOverdrive
PistonRetainer
1 - PISTON RETAINER
2 - SPECIAL TOOL SP-5124
21 - 240
OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(7) Hold puller plate and bolt in place and install
puller nut SP-3701 on puller bolt (Fig. 207).
(8) Tighten puller nut to press clutch cam into case (Fig. 207). Be sure cam is pressed into case evenly and does not become cocked.
(9) Remove clutch cam installer tools. (10) Stake case in 14 places around clutch cam to help secure cam in case. Use blunt punch or chisel to stake case.
(11) Remove piston retainer
from case. Cover retainer with plastic sheeting, or paper to keep it dust free.
(12) Clean case and cam thoroughly. Be sure any chips/shavings generated during cam installation are removed from case.
Fig.208Installing/AligningCaseGasket
1 - CASE GASKET 2 - BE SURE GOVERNOR TUBE FEED HOLES IN CASE AND GASKET ARE ALIGNED
Fig.209AligningOverdrivePistonRetainer
1 - PISTON RETAINER 2 - GASKET 3 - RETAINER BOLTS
(17) Position Guide Ring 8114-1 on outer edge of
overdrive piston retainer.
overdrive piston retainer.
(18) Position Seal Guide 8114-3 on inner edge of
Fig.207PressingOverrunningClutchCamInto
Case
1 - SPECIAL TOOL SP-3583-A
2 - TIGHTEN NUT TO DRAW CAM INTO CASE (NUT IS PART OF
BOLT SP-3701)
3 - SPECIAL TOOL SP-5124
4 - SPECIAL TOOL SP-3701
(13) Install new gasket at rear of transmission case. Use petroleum jelly to hold gasket in place. Be sure to align governor feed holes in gasket with feed passages in case (Fig. 208). Also install gasket before overdrive piston retainer. Center hole in gasket is smaller than retainer and cannot be installed over retainer.
(14) Position overdrive piston retainer on trans- mission case and align bolt holes in retainer, gasket and case (Fig. 209). Then install and tighten retainer bolts to 17 N·m (13 ft. lbs.) torque.
(15) Install new seals on overdrive piston. (16) Stand transmission case upright on bellhous-
ing.
DR OVERRUNNING CLUTCH CAM/OVERDRIVE PISTON RETAINER (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 241
(19) Install overdrive piston in overdrive piston retainer by: aligning locating lugs on overdrive piston to the two mating holes in retainer.
(a) Aligning locating lugs on overdrive piston to
the two mating holes in retainer.
(b) Lubricate overdrive piston seals with Mopart
Door Ease, or equivalent.
inside Guide Ring 8114-1.
(c) Install piston over Seal Guide 8114-3 and
(d) Push overdrive piston into position in
retainer.
(e) Verify that the locating lugs entered the lug
bores in the retainer.
PISTONS DESCRIPTION
There are several sizes and types of pistons used in an automatic transmission. Some pistons are used to apply clutches, while others are used to apply bands. They all have in common the fact that they are round or circular in shape, located within a smooth walled cylinder, which is closed at one end and con- verts fluid pressure into mechanical movement. The fluid pressure exerted on the piston is contained within the system through the use of piston rings or seals.
OPERATION
The principal which makes this operation possible is known as Pascal’s Law. Pascal’s Law can be stated as: “Pressure on a confined fluid is transmitted equally in all directions and acts with equal force on equal areas.â€
PRESSURE
Pressure (Fig. 210)
is nothing more than force
(lbs.) divided by area (in or ft.), or force per unit
area. Given a 100 lb. block and an area of 100 sq. in.
on the floor, the pressure exerted by the block is: 100
lbs. 100 in or 1 pound per square inch, or PSI as it is
commonly referred to.
PRESSURE ON A CONFINED FLUID
Pressure is exerted on a confined fluid (Fig. 211) by applying a force to some given area in contact with the fluid. A good example of this is a cylinder filled with fluid and equipped with a piston that is closely fitted to the cylinder wall. If a force is applied to the piston, pressure will be developed in the fluid. Of course, no pressure will be created if the fluid is not confined. It will simply “leak†past the piston. There must be a resistance to flow in order to create pres- sure. Piston sealing is extremely important in hydraulic operation. Several kinds of seals are used
Fig.210ForceandPressureRelationship
to accomplish this within a transmission. These
include but are not limited to O-rings, D-rings, lip
seals, sealing rings, or extremely close tolerances
between the piston and the cylinder wall. The force
exerted is downward (gravity), however, the principle
remains the same no matter which direction is taken.
The pressure created in the fluid is equal to the force
applied, divided by the piston area. If the force is 100
lbs., and the piston area is 10 sq. in., then the pres-
sure created equals 10 PSI. Another interpretation of
Pascal’s Law is that regardless of container shape or
size, the pressure will be maintained throughout, as
long as the fluid is confined. In other words, the
pressure in the fluid is the same everywhere within
the container.
Fig.211PressureonaConfinedFluid
DR
AUTOMATIC TRANSMISSION - 46RE
21 - 242
PISTONS (Continued)
FORCE MULTIPLICATION
Using the 10 PSI example used in the illustration (Fig. 212), a force of 1000 lbs. can be moved with a force of only 100 lbs. The secret of force multiplica- tion in hydraulic systems is the total fluid contact area employed. The illustration, (Fig. 212), shows an area that is ten times larger than the original area. The pressure created with the smaller 100 lb. input is 10 PSI. The concept “pressure is the same every- where†means that the pressure underneath the larger piston is also 10 PSI. Pressure is equal to the force applied divided by the contact area. Therefore, by means of simple algebra, the output force may be found. This concept is extremely important, as it is also used in the design and operation of all shift valves and limiting valves in the valve body, as well as the pistons, of the transmission, which activate the clutches and bands. It is nothing more than using a difference of area to create a difference in pressure to move an object.
Fig.213PistonTravel
PLANETARY GEARTRAIN/ OUTPUT SHAFT DESCRIPTION
The planetary gearsets (Fig. 214) are designated as the front, rear, and overdrive planetary gear assem- blies and located in such order. A simple planetary gearset consists of three main members:
Fig.212ForceMultiplication
PISTON TRAVEL
The relationship between hydraulic lever and a
mechanical
lever is the same. With a mechanical
lever it’s a weight-to-distance output rather than a
pressure-to-area output. Using the same forces and
areas as in the previous example, the smaller piston
(Fig. 213) has to move ten times the distance
required to move the larger piston one inch. There-
fore,
for every inch the larger piston moves, the
smaller piston moves ten inches. This principle is
true in other instances also. A common garage floor
jack is a good example. To raise a car weighing 2000
lbs., an effort of only 100 lbs. may be required. For
every inch the car moves upward, the input piston at
the jack handle must move 20 inches downward.
Fig.214PlanetaryGearset
1 - ANNULUS GEAR 2 - SUN GEAR 3 - PLANET CARRIER 4 - PLANET PINIONS (4)
AUTOMATIC TRANSMISSION - 46RE
DR PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued) †The sun gear which is at the center of the sys- tem.†The planet carrier with planet pinion gears which are free to rotate on their own shafts and are in mesh with the sun gear. †The annulus gear, which rotates around and is in mesh with the planet pinion gears.
21 - 243
NOTE: The number of pinion gears does not affect the gear ratio, only the duty rating.
OPERATION
With any given planetary gearset, several condi- tions must be met for power to be able to flow: †One member must be held. †Another member must be driven or used as an input.†The third member may be used as an output for power flow. †For direct drive to occur, two gear members in
the front planetary gearset must be driven.
NOTE: Gear ratios are dependent on the number of teeth on the annulus and sun gears.
DISASSEMBLY
Fig.216RemovingFrontPlanetaryAndAnnulus
Gears
1 - DRIVING SHELL 2 - FRONT ANNULUS GEAR 3 - FRONT PLANETARY GEAR
(1) Remove planetary snap-ring from intermediate shaft (Fig. 215). Discard snap-ring as it is not reus- able.
(2) Remove front planetary gear and front annulus
gear as assembly (Fig. 216).
(3) Remove
front planetary gear and thrust washer from front annulus gear (Fig. 217). Note thrust washer position for assembly reference.
Fig.217DisassemblingFrontPlanetaryAnd
AnnulusGears
1 - FRONT PLANETARY GEAR 2 - TABBED THRUST WASHER 3 - FRONT ANNULUS GEAR
Fig.215RemovingPlanetarySnap-Ring
1 - PLANETARY SNAP-RING
21 - 244
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(4) Remove tabbed thrust washer from driving shell (Fig. 218). Note washer position for assembly reference.
(5) Remove sun gear and driving shell as assembly
(Fig. 219).
Fig.220RearPlanetaryThrustWasherRemoval
1 - SUN GEAR 2 - REAR PLANETARY THRUST WASHER 3 - DRIVING SHELL
Fig.218DrivingShellThrustWasherRemoval
1 - DRIVING SHELL 2 - TABBED THRUST WASHER 3 - SUN GEAR
Fig.221RearPlanetaryAndAnnulusGearRemoval 1 - INTERMEDIATE SHAFT 2 - REAR ANNULUS GEAR 3 - REAR PLANETARY GEAR
Fig.219SunGearAndDrivingShellRemoval
1 - INTERMEDIATE SHAFT 2 - DRIVING SHELL 3 - SUN GEAR
(6) Remove tabbed thrust washer from rear plane- tary gear (Fig. 220). Note washer position on gear for assembly reference.
(7) Remove rear planetary gear and rear annulus
gear from intermediate shaft (Fig. 221).
(8) Remove thrust plate from rear annulus gear
(Fig. 222).
Fig.222RearAnnulusThrustPlateRemoval
1 - REAR ANNULUS GEAR 2 - THRUST PLATE
DR PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued) INSPECTION
AUTOMATIC TRANSMISSION - 46RE
21 - 245
sun gear and against rear side of driving shell (Fig. 223). Install rear snap-ring to secure sun gear and thrust plate in driving shell.
(3) Install rear annulus gear on intermediate shaft
(Fig. 224).
(4) Install thrust plate in annulus gear (Fig. 225). Be sure plate is seated on shaft splines and against gear.
Inspect the planetary gear sets and annulus gears. The planetary pinions, shafts, washers, and retaining pins are serviceable. However, if a pinion carrier is damaged, the entire planetary gear set must be replaced as an assembly.
Replace the annulus gears if the teeth are chipped, broken, or worn, or the gear is cracked. Replace the planetary thrust plates and the tabbed thrust wash- ers if cracked, scored or worn.
Inspect the machined surfaces of the intermediate shaft. Be sure the oil passages are open and clear. Replace the shaft if scored, pitted, or damaged.
Inspect the sun gear and driving shell. If either component is worn or damaged, remove the sun gear rear retaining ring and separate the sun gear and thrust plate from the driving shell. Then replace the necessary component.
Replace the sun gear as an assembly if the gear teeth are chipped or worn. Also replace the gear as an assembly if the bushings are scored or worn. The sun gear bushings are not serviceable. Replace the thrust plate if worn, or severely scored. Replace the driving shell if distorted, cracked, or damaged in any way.
Replace all snap-rings during geartrain assembly.
Reusing snap-rings is not recommended.
ASSEMBLY
(1) Lubricate sun gear and planetary gears with transmission fluid during assembly. Use petroleum jelly to lubricate intermediate shaft bushing surfaces, thrust washers and thrust plates and to hold these parts in place during assembly.
(2) Install front snap-ring on sun gear and install gear in driving shell. Then install thrust plate over
Fig.223SunGearInstallation
1 - DRIVING SHELL 2 - SUN GEAR 3 - THRUST PLATE 4 - SUN GEAR REAR RETAINING RING
Fig.224InstallingRearAnnulusGearOn
IntermediateShaft
1 - REAR ANNULUS GEAR 2 - OUTPUT SHAFT
Fig.225InstallingRearAnnulusThrustPlate
1 - REAR ANNULUS GEAR 2 - THRUST PLATE
21 - 246
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(5) Install rear planetary gear in rear annulus gear (Fig. 226). Be sure planetary carrier is seated against annulus gear.
(6) Install tabbed thrust washer on front face of rear planetary gear (Fig. 227). Seat washer tabs in matching slots in face of gear carrier. Use extra petroleum jelly to hold washer in place if desired.
(7) Lubricate sun gear bushings with petroleum
jelly or transmission fluid.
(8) Install sun gear and driving shell on interme- diate shaft (Fig. 228). Seat shell against rear plane- tary gear. Verify that thrust washer on planetary gear was not displaced during installation.
(9) Install tabbed thrust washer in driving shell (Fig. 229), be sure washer tabs are seated in tab slots of driving shell. Use extra petroleum jelly to hold washer in place if desired.
Fig.228InstallingSunGearAndDrivingShell
1 - OUTPUT SHAFT 2 - DRIVING SHELL 3 - REAR PLANETARY GEAR 4 - OUTPUT SHAFT 5 - SUN GEAR
Fig.226InstallingRearPlanetaryGear
1 - REAR ANNULUS GEAR 2 - REAR PLANETARY GEAR
Fig.227InstallingRearPlanetaryThrustWasher
1 - REAR PLANETARY GEAR 2 - TABBED THRUST WASHER
Fig.229InstallingDrivingShellThrustWasher
1 - TAB SLOTS (3) 2 - DRIVING SHELL 3 - TABBED THRUST WASHER
DR PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 247
(10) Install tabbed thrust washer on front plane- tary gear (Fig. 230). Seat washer tabs in matching slots in face of gear carrier. Use extra petroleum jelly to hold washer in place if desired.
Fig.231AssemblingFrontPlanetaryAndAnnulus
Gears
1 - FRONT ANNULUS GEAR 2 - FRONT PLANETARY GEAR
Fig.230InstallingThrustWasherOnFront
PlanetaryGear
1 - TABBED THRUST WASHER 2 - FRONT PLANETARY GEAR
(11) Install front annulus gear over and onto front planetary gear (Fig. 231). Be sure gears are fully meshed and seated.
(12) Install
front planetary and annulus gear assembly (Fig. 232). Hold gears together and slide them onto shaft. Be sure planetary pinions are seated on sun gear and that planetary carrier is seated on intermediate shaft.
(13) Place geartrain in upright position. Rotate gears to be sure all components are seated and prop- erly assembled. Snap-ring groove at forward end of intermediate shaft will be completely exposed when components are assembled correctly.
Fig.232InstallingFrontPlanetaryAndAnnulus
GearAssembly
1 - DRIVING SHELL 2 - ASSEMBLED FRONT PLANETARY AND ANNULUS GEARS
21 - 248
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(14) Install new planetary snap-ring in groove at
end of intermediate shaft (Fig. 233).
(15) Turn planetary geartrain over. Position wood block under front end of intermediate shaft and sup- port geartrain on shaft. Be sure all geartrain parts have moved forward against planetary snap-ring. This is important for accurate end play check.
(16) Check planetary geartrain end play with feeler gauge (Fig. 234). Insert gauge between rear annulus gear and shoulder on intermediate shaft as shown. End play should be 0.15 to 1.22 mm (0.006 to 0.048 in.).
(17) If end play is incorrect, install thinner/thicker
planetary snap-ring as needed.
Fig.234CheckingPlanetaryGeartrainEndPlay
1 - OUTPUT SHAFT 2 - REAR ANNULUS GEAR 3 - FEELER GAUGE
REAR CLUTCH DESCRIPTION
The rear clutch assembly (Fig. 235) is composed of the rear clutch retainer, pressure plate, clutch plates, driving discs, piston, Belleville spring, and snap- rings. The Belleville spring acts as a lever to multi- ply the force applied on to it by the apply piston. The increased apply force on the rear clutch pack, in com- parison to the front clutch pack, is needed to hold against the greater torque load imposed onto the rear pack. The rear clutch is directly behind the front clutch and is considered a driving component.
NOTE: The number of discs and plates may vary with each engine and vehicle combination.
Fig.233InstallingPlanetarySnap-Ring
1 - SNAP-RING PLIERS 2 - PLANETARY SNAP-RING
DR REAR CLUTCH (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 249
1 - REAR CLUTCH RETAINER 2 - TORLONâ„¢ SEAL RINGS 3 - INPUT SHAFT 4 - PISTON RETAINER 5 - OUTPUT SHAFT THRUST WASHER 6 - INNER PISTON SEAL 7 - PISTON SPRING 8 - PRESSURE PLATE 9 - CLUTCH DISCS 10 - SNAP-RING (SELECTIVE)
Fig.235RearClutchComponents
11 - REACTION PLATE 12 - CLUTCH PLATES 13 - WAVE SPRING 14 - SPACER RING 15 - PISTON 16 - OUTER PISTON SEAL 17 - REAR SEAL RING 18 - FIBER THRUST WASHER 19 - RETAINING RING
OPERATION
To apply the clutch, pressure is applied between the clutch retainer and piston. The fluid pressure is provided by the oil pump, transferred through the control valves and passageways, and enters the clutch through the hub of the reaction shaft support. With pressure applied between the clutch retainer and piston, the piston moves away from the clutch retainer and compresses the clutch pack. This action applies the clutch pack, allowing torque to flow through the input shaft into the driving discs, and into the clutch plates and pressure plate that are lugged to the clutch retainer. The waved spring is used to cushion the application of the clutch pack. The snap-ring is selective and used to adjust clutch pack clearance.
When pressure is released from the piston, the spring returns the piston to its fully released position and disengages the clutch. The release spring also helps to cushion the application of the clutch assem- bly. When the clutch is in the process of being released by the release spring, fluid flows through a vent and one-way ball-check-valve located in the pis-
ton. The check-valve is needed to eliminate the pos- sibility of plate drag caused by centrifugal force acting on the residual fluid trapped in the clutch pis- ton retainer.
DISASSEMBLY
(1) Remove fiber thrust washer from forward side
of clutch retainer.
(2) Remove input shaft front and rear seal rings. (3) Remove selective clutch pack snap-ring (Fig.
236).
(4) Remove the reaction plate, clutch discs, steel plates, pressure plate, wave spring, spacer ring, and piston spring (Fig. 236).
(5) Remove clutch piston with rotating motion. (6) Remove and discard piston seals. (7) Remove input shaft retaining ring. It may be necessary to press the input shaft in slightly to relieve tension on the retaining ring
(8) Press input shaft out of retainer with shop press and suitable size press tool. Use a suitably sized press tool to support the retainer as close to the input shaft as possible.
21 - 250
REAR CLUTCH (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
1 - REAR CLUTCH RETAINER 2 - TORLONâ„¢ SEAL RINGS 3 - INPUT SHAFT 4 - PISTON RETAINER 5 - OUTPUT SHAFT THRUST WASHER 6 - INNER PISTON SEAL 7 - PISTON SPRING 8 - PRESSURE PLATE 9 - CLUTCH DISCS 10 - SNAP-RING (SELECTIVE)
Fig.236RearClutchComponents
11 - REACTION PLATE 12 - CLUTCH PLATES 13 - WAVE SPRING 14 - SPACER RING 15 - PISTON 16 - OUTER PISTON SEAL 17 - REAR SEAL RING 18 - FIBER THRUST WASHER 19 - RETAINING RING
CLEANING
Clean the clutch components with solvent and dry them with compressed air. Do not use rags or shop towels to dry any of the clutch parts. Lint from such materials will adhere to component surfaces and could restrict or block fluid passages after assembly.
INSPECTION
Replace the clutch discs if warped, worn, scored, burned/charred, the lugs are damaged, or if the fac- ing is flaking off. Replace the top and bottom pres- sure plates if scored, warped, or cracked. Be sure the driving lugs on the pressure and clutch plates are also in good condition. The lugs must not be bent, cracked or damaged in any way.
Replace the piston spring and wave spring if either
part is distorted, warped or broken.
Check the lug grooves in the clutch retainer. The clutch and pressure plates should slide freely in the slots. Replace the retainer if the grooves are worn or damaged. Also check action of the check balls in the retainer and piston. Each check ball must move freely and not stick.
Replace the retainer bushing if worn, scored, or
doubt exists about bushing condition.
Inspect the piston and retainer seal surfaces for nicks or scratches. Minor scratches can be removed with crocus cloth. However, replace the piston and/or retainer if the seal surfaces are seriously scored.
Check condition of the fiber thrust washer and metal output shaft thrust washer. Replace either washer if worn or damaged.
Check condition of the seal rings on the input shaft and clutch retainer hub. Replace the seal rings only if worn, distorted, or damaged. The input shaft front seal ring is teflon with chamfered ends. The rear ring is metal with interlocking ends.
Check the input shaft for wear, or damage. Replace
the shaft if worn, scored or damaged in any way.
ASSEMBLY
(1) Soak clutch discs in transmission fluid while
assembling other clutch parts.
(2) Install new seal rings on clutch retainer hub
and input shaft if necessary.
(a) Be sure clutch hub seal ring is fully seated in
groove and is not twisted.
DR REAR CLUTCH (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 251
(3) Lubricate splined end of input shaft and clutch retainer with transmission fluid. Then partially press input shaft into retainer (Fig. 237). Use a suitably sized press tool to support retainer as close to input shaft as possible.
(4) Install input shaft retaining ring. (5) Press the input shaft the remainder of the way
into the clutch retainer.
(6) Install new seals on clutch piston. Be sure lip
of each seal faces interior of clutch retainer.
(7) Lubricate lip of piston seals with generous quantity of Mopart Door Ease. Then lubricate retainer hub and bore with light coat of transmission fluid.
(8) Install clutch piston in retainer. Use twisting motion to seat piston in bottom of retainer. A thin strip of plastic (about 0.0209 thick), can be used to guide seals into place if necessary.
CAUTION: Never push the clutch piston straight in. This will fold the seals over causing leakage and clutch slip. In addition, never use any type of metal tool to help ease the piston seals into place. Metal tools will cut, shave, or score the seals.
(9) Install piston spring in retainer and on top of piston. Concave side of spring faces downward (toward piston).
(10) Install the spacer ring and wave spring into the retainer. Be sure spring is completely seated in retainer groove.
(11) Install pressure plate (Fig. 236). Ridged side of plate faces downward (toward piston) and flat side toward clutch pack.
(12) Install first clutch disc in retainer on top of pressure plate. Then install a clutch plate followed by a clutch disc until entire clutch pack is installed (4 discs and 3 plates are required) (Fig. 236).
(13) Install the reaction plate. (14) Install selective snap-ring. Be sure snap-ring
is fully seated in retainer groove.
(15) Using a suitable gauge bar and dial indicator,
measure clutch pack clearance (Fig. 238).
(a) Position gauge bar across the clutch drum indicator pointer on the pressure
with the dial plate (Fig. 238).
(b) Using two small screw drivers, lift the pres-
sure plate and release it.
(c) Zero the dial indicator. (d) Lift the pressure plate until it contacts the
snap-ring and record the dial indicator reading. Clearance should be 0.635 - 0.914 mm (0.025 - 0.036 in.). If clearance is incorrect, steel plates, discs, selective snap ring and pressure plates may have to be changed.
The selective snap ring thicknesses are: †0.107 - 0.109 in.
Fig.237PressingInputShaftIntoRearClutch
Retainer
1 - INPUT SHAFT 2 - REAR CLUTCH RETAINER 3 - PRESS RAM
Fig.238CheckingRearClutchPackClearance
1 - DIAL INDICATOR 2 - PRESSURE PLATE 3 - SNAP-RING 4 - STAND 5 - REAR CLUTCH 6 - GAUGE BAR
†0.098 - 0.100 in. †0.095 - 0.097 in. †0.083 - 0.085 in. †0.076 - 0.078 in. †0.071 - 0.073 in. †0.060 - 0.062 in.
21 - 252
REAR CLUTCH (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(16) Coat rear clutch thrust washer with petro- leum jelly and install washer over input shaft and into clutch retainer (Fig. 239). Use enough petroleum jelly to hold washer in place.
(17) Set rear clutch aside for installation during
final assembly.
DISASSEMBLY
(1) Remove small snap-ring and remove plug and
spring from servo piston (Fig. 240).
(2) Remove and discard servo piston seal ring.
Fig.239InstallingRearClutchThrustWasher
1 - REAR CLUTCH RETAINER 2 - REAR CLUTCH THRUST WASHER
REAR SERVO DESCRIPTION
The rear (low/reverse) servo consists of a single stage or diameter piston and a spring loaded plug. The spring is used to cushion the application of the rear (low/reverse) band.
OPERATION
While in the de-energized state (no pressure applied), the piston is held up in its bore by the pis- ton spring. The plug is held down in its bore, in the piston, by the plug spring. When pressure is applied to the top of the piston, the plug is forced down in its bore, taking up any clearance. As the piston moves, it causes the plug spring to compress, and the piston moves down over the plug. The piston continues to move down until it hits the shoulder of the plug and fully applies the band. The period of time from the initial application, until the piston is against the shoulder of the plug, represents a reduced shocking of the band that cushions the shift.
Fig.240RearServoComponents
1 - SNAP-RING 2 - PISTON SEAL 3 - PISTON PLUG 4 - SPRING RETAINER 5 - SNAP-RING 6 - PISTON SPRING 7 - CUSHION SPRING 8 - PISTON
CLEANING
Remove and discard the servo piston seal ring (Fig. 241). Then clean the servo components with solvent and dry with compressed air. Replace either spring if collapsed, distorted or broken. Replace the plug and piston if cracked, bent, or worn. Discard the servo snap-rings and use new ones at assembly.
Fig.241RearServoComponents
1 - SNAP-RING 2 - PISTON SEAL 3 - PISTON PLUG 4 - SPRING RETAINER 5 - SNAP-RING 6 - PISTON SPRING 7 - CUSHION SPRING 8 - PISTON
DR REAR SERVO (Continued) ASSEMBLY
(1) Lubricate piston and guide seals (Fig. 242) with petroleum jelly. Lubricate other servo parts with Mopart ATF +4, Automatic Transmission fluid.
(2) Install new seal ring on servo piston. (3) Assemble piston, plug, spring and new snap-
ring.
(4) Lubricate piston seal lip with petroleum jelly.
Fig.242RearServoComponents
1 - SNAP-RING 2 - PISTON SEAL 3 - PISTON PLUG 4 - SPRING RETAINER 5 - SNAP-RING 6 - PISTON SPRING 7 - CUSHION SPRING 8 - PISTON
SHIFT MECHANISM DESCRIPTION
The gear shift mechanism provides six shift posi- tions which are: †PARK (P) †REVERSE (R) †NEUTRAL (N) †DRIVE (D) †Manual SECOND (2) †Manual LOW (1)
OPERATION
Manual LOW (1) range provides first gear only. Overrun braking is also provided in this range. Man- ual SECOND (2) range provides first and second gear only.
DRIVE range provides first, second third and over- drive fourth gear ranges. The shift into overdrive fourth gear range occurs only after the transmission has completed the shift into D third gear range. No further movement of the shift mechanism is required to complete the 3-4 shift.
The fourth gear upshift occurs automatically when the overdrive selector switch is in the ON position. No upshift to fourth gear will occur if any of the fol- lowing are true:
AUTOMATIC TRANSMISSION - 46RE
21 - 253
C (50° F) or above 121° C (250° F).
†The transmission fluid temperature is below 10° †The shift to third is not yet complete. †Vehicle speed is too low for the 3-4 shift to occur. †Battery temperature is below -5° C (23° F).
SOLENOID DESCRIPTION
The typical electrical solenoid used in automotive applications is a linear actuator. It is a device that produces motion in a straight line. This straight line motion can be either forward or backward in direc- tion, and short or long distance.
A solenoid is an electromechanical device that uses a magnetic force to perform work. It consists of a coil of wire, wrapped around a magnetic core made from steel or iron, and a spring loaded, movable plunger, which performs the work, or straight line motion.
The solenoids used in transmission applications are attached to valves which can be classified as nor- mally open or normally closed. The normally open solenoid valve is defined as a valve which allows hydraulic flow when no current or voltage is applied to the solenoid. The normally closed sole- noid valve is defined as a valve which does not allow hydraulic flow when no current or voltage is applied to the solenoid. These valves perform hydraulic con- trol functions for the transmission and must there- fore be durable and tolerant of dirt particles. For these reasons, the valves have hardened steel pop- pets and ball valves. The solenoids operate the valves directly, which means that the solenoids must have very high outputs to close the valves against the siz- able flow areas and line pressures found in current transmissions. Fast response time is also necessary to ensure accurate control of the transmission.
The strength of the magnetic field is the primary force that determines the speed of operation in a par- ticular solenoid design. A stronger magnetic field will cause the plunger to move at a greater speed than a weaker one. There are basically two ways to increase the force of the magnetic field:
1. Increase the amount of current applied to the
coil or
2. Increase the number of turns of wire in the coil. The most common practice is to increase the num- ber of turns by using thin wire that can completely fill the available space within the solenoid housing. The strength of the spring and the length of the plunger also contribute to the response speed possi- ble by a particular solenoid design.
A solenoid can also be described by the method by which it the possibilities include variable force, pulse-width modulated, con-
is controlled. Some of
21 - 254
SOLENOID (Continued)
AUTOMATIC TRANSMISSION - 46RE
stant ON, or duty cycle. The variable force and pulse- width modulated versions utilize similar methods to control the current flow through the solenoid to posi- tion the solenoid plunger at a desired position some- where between full ON and full OFF. The constant ON and duty cycled versions control the voltage across the solenoid to allow either full flow or no flow through the solenoid’s valve.
OPERATION
When an electrical current is applied to the sole- noid coil, a magnetic field is created which produces an attraction to the plunger, causing the plunger to move and work against the spring pressure and the load applied by the fluid the valve is controlling. The plunger is normally directly attached to the valve which it is to operate. When the current is removed from the coil, the attraction is removed and the plunger will return to its original position due to spring pressure.
The plunger is made of a conductive material and accomplishes this movement by providing a path for the magnetic field to flow. By keeping the air gap between the plunger and the coil to the minimum necessary to allow free movement of the plunger, the magnetic field is maximized.
SPEED SENSOR DESCRIPTION
The speed sensor (Fig. 243) is located in the over- drive gear case. The sensor is positioned over the park gear and monitors transmission output shaft rotating speed.
Fig.243TransmissionOutputSpeedSensor
1 - TRANSMISSION OUTPUT SHAFT SPEED SENSOR 2 - SEAL
OPERATION
Speed sensor signals are triggered by the park gear lugs as they rotate past the sensor pickup face. Input signals from the sensor are sent to the transmission control module for processing. Signals from this sensor are shared with the powertrain control module.
DR
THROTTLE VALVE CABLE DESCRIPTION
Transmission throttle valve cable (Fig. 244) adjust- ment is extremely important to proper operation. This adjustment positions the throttle valve, which controls shift speed, quality, and part-throttle down- shift sensitivity.
If cable setting is too loose, early shifts and slip- page between shifts may occur. If the setting is too tight, shifts may be delayed and part throttle down- shifts may be very sensitive.
Fig.244ThrottleValveCableAttachment-At
Engine
1 - THROTTLE VALVE CABLE 2 - CABLE BRACKET 3 - THROTTLE BODY LEVER 4 - ACCELERATOR CABLE 5 - SPEED CONTROL CABLE
The transmission throttle valve is operated by a cam on the throttle lever. The throttle lever is oper- ated by an adjustable cable (Fig. 245). The cable is attached to an arm mounted on the throttle lever shaft. A retaining clip at the engine-end of the cable is removed to provide for cable adjustment. The retaining clip is then installed back onto the throttle valve cable to lock in the adjustment.
DR THROTTLE VALVE CABLE (Continued)
AUTOMATIC TRANSMISSION - 46RE
21 - 255
Fig.245ThrottleValveCableatThrottleLinkage
1 - THROTTLE LINKAGE 2 - THROTTLE VALVE CABLE LOCKING CLIP 3 - THROTTLE VALVE CABLE
ADJUSTMENTS - THROTTLE VALVE CABLE
A correctly adjusted throttle valve cable will cause the throttle lever on the transmission to move simul- taneously with the throttle body lever from the idle position. Proper adjustment will allow simultaneous movement without causing the transmission throttle lever to either move ahead of, or lag behind the lever on the throttle body.
ADJUSTMENT VERIFICATION
(1) Turn ignition key to OFF position. (2) Remove air cleaner. (3) Verify that lever on throttle body is at curb idle position (Fig. 246). Then verify that the transmission throttle lever (Fig. 247) is also at idle (fully forward) position.
(4) Slide cable off attachment stud on throttle body
lever.
stud on throttle body lever:
(5) Compare position of cable end to attachment †Cable end and attachment stud should be aligned (or centered on one another) to within 1 mm (0.039 in.) in either direction (Fig. 248).
Fig.246ThrottleValveCableAttachment-At
Engine
1 - THROTTLE VALVE CABLE 2 - CABLE BRACKET 3 - THROTTLE BODY LEVER 4 - ACCELERATOR CABLE 5 - SPEED CONTROL CABLE
Fig.247ThrottleValveCableatTransmission
1 - TRANSMISSION SHIFTER CABLE 2 - THROTTLE VALVE CABLE 3 - TRANSFER CASE SHIFTER CABLE 4 - TRANSFER CASE SHIFTER CABLE BRACKET RETAINING BOLT (1 OR 2) 5 - THROTTLE VALVE CABLE BRACKET RETAINING BOLT 6 - ELECTRICAL CONNECTORS 7 - TRANSMISSION FLUID LINES
AUTOMATIC TRANSMISSION - 46RE
21 - 256
THROTTLE VALVE CABLE (Continued)
†If cable end and attachment stud are misaligned
(off center), cable will have to be adjusted as
described in Throttle Valve Cable Adjustment proce-
dure.
DR
if throttle body lever prevents be necessary. Or, transmission lever from returning to closed position, cable adjustment will be necessary.
ADJUSTMENT PROCEDURE
(1) Turn ignition switch to OFF position. (2) Remove air cleaner if necessary. (3) Disconnect cable end from attachment stud. Carefully slide cable off stud. Do not pry or pull cable off.
(4) Verify that transmission throttle lever is in fully closed position. Then be sure lever on throttle body is at curb idle position.
(5) Pry the T.V. cable lock (A) into the UP position (Fig. 248). This will unlock the cable and allow for readjustment.
(6) Apply just enough tension on the T.V. cable (B) to remove any slack in the cable.Pulling too tight will cause the T.V. lever on the transmission to move out of its idle position, which will result in an incorrect T.V. cable adjustment. Slide the sheath of the T.V. cable (D) back and forth until the centerlines of the T.V. cable end (B) and the throttle bell crank lever (C) are aligned within one millimeter (1mm) (Fig. 248).
(7) While holding the T.V. cable in the set position push the T.V. cable lock (A) into the down position (Fig. 248). This will lock the present T.V. cable adjustment.
NOTE: Be sure that as the cable is pulled forward and centered on the throttle lever stud, the cable housing moves smoothly with the cable. Due to the angle at which the cable housing enters the spring housing, the cable housing may bind slightly and create an incorrect adjustment.
(8) Reconnect the T.V. cable (B) to the throttle
bellcrank lever (C).
(9) Check cable adjustment. Verify transmission throttle lever and lever on throttle body move simul- taneously.
Fig.248ThrottleValveCableatThrottleLinkage
1 - THROTTLE LINKAGE 2 - THROTTLE VALVE CABLE LOCKING CLIP 3 - THROTTLE VALVE CABLE
(6) Reconnect cable end to attachment stud. Then with aid of a helper, observe movement of transmis- sion throttle lever and lever on throttle body. †If both levers move simultaneously from idle to half-throttle and back to idle position, adjustment is correct. †If transmission throttle lever moves ahead of, or lags behind throttle body lever, cable adjustment will
DR
AUTOMATIC TRANSMISSION - 46RE
21 - 257
TORQUE CONVERTER DESCRIPTION
The torque converter (Fig. 249)
is a hydraulic device that couples the engine crankshaft to the transmission. The torque converter consists of an outer shell with an internal turbine, a stator, an overrunning clutch, an impeller and an electronically applied converter clutch. The converter clutch pro- vides reduced engine speed and greater fuel economy when engaged. Clutch engagement also provides reduced transmission fluid temperatures. The torque converter hub drives the transmission oil (fluid) pump.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
CAUTION: The torque converter must be replaced if a transmission failure resulted in large amounts of metal or fiber contamination in the fluid.
Fig.249TorqueConverterAssembly
1 - TURBINE 2 - IMPELLER 3 - HUB 4 - STATOR 5 - FRONT COVER 6 - CONVERTER CLUTCH DISC 7 - DRIVE PLATE
21 - 258
TORQUE CONVERTER (Continued)
AUTOMATIC TRANSMISSION - 46RE
IMPELLER
The impeller (Fig. 250) is an integral part of the converter housing. The impeller consists of curved blades placed radially along the inside of the housing on the transmission side of the converter. As the con- verter housing is rotated by the engine, so is the impeller, because they are one and the same and are the driving members of the system.
DR
1 - ENGINE FLEXPLATE 2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE SECTION 3 - IMPELLER VANES AND COVER ARE INTEGRAL
Fig.250Impeller
4 - ENGINE ROTATION 5 - ENGINE ROTATION
AUTOMATIC TRANSMISSION - 46RE
21 - 259
DR TORQUE CONVERTER (Continued) TURBINE
The turbine (Fig. 251) is the output, or driven, member of the converter. The turbine is mounted within the housing opposite the impeller, but is not attached to the housing. The input shaft is inserted through the center of the impeller and splined into the turbine. The design of the turbine is similar to the impeller, except the blades of the turbine are curved in the opposite direction.
1 - TURBINE VANE 2 - ENGINE ROTATION 3 - INPUT SHAFT
Fig.251Turbine
4 - PORTION OF TORQUE CONVERTER COVER 5 - ENGINE ROTATION 6 - OIL FLOW WITHIN TURBINE SECTION
AUTOMATIC TRANSMISSION - 46RE
21 - 260
TORQUE CONVERTER (Continued)
STATOR
The stator assembly (Fig. 252) is mounted on a sta- tionary shaft which is an integral part of the oil pump. The stator is located between the impeller and turbine within the torque converter case (Fig. 253). The stator contains an over-running clutch, which allows the stator to rotate only in a clockwise direc- tion. When the stator is locked against the over-run- ning clutch, the torque multiplication feature of the torque converter is operational.
DR
Fig.252StatorComponents
1 - CAM (OUTER RACE) 2 - ROLLER 3 - SPRING 4 - INNER RACE
TORQUE CONVERTER CLUTCH (TCC)
The TCC (Fig. 254) was installed to improve the efficiency of the torque converter that is lost to the slippage of the fluid coupling. Although the fluid cou- pling provides smooth, shock-free power transfer, it is natural for all fluid couplings to slip. If the impeller and turbine were mechanically locked together, a zero slippage condition could be obtained. A hydraulic piston was added to the turbine, and a friction mate- rial was added to the inside of the front cover to pro- vide this mechanical lock-up.
Fig.253StatorLocation
1 - STATOR 2 - IMPELLER 3 - FLUID FLOW 4 - TURBINE
Fig.254TorqueConverterClutch(TCC)
1 - IMPELLER FRONT COVER 2 - THRUST WASHER ASSEMBLY 3 - IMPELLER 4 - STATOR 5 - TURBINE 6 - PISTON 7 - FRICTION DISC
DR TORQUE CONVERTER (Continued) OPERATION
The converter impeller (Fig. 255) (driving member), which is integral to the converter housing and bolted to the engine drive plate, rotates at engine speed. The converter turbine (driven member), which reacts from fluid pressure generated by the impeller, rotates and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel- ler blades strikes the blades of the turbine, some of the energy and rotational force is transferred into the turbine and the input shaft. This causes both of them (turbine and input shaft) to rotate in a clockwise direction following the impeller. As the fluid is leav- ing the trailing edges of the turbine’s blades it con- tinues in a “hindering†direction back toward the impeller. If the fluid is not redirected before it strikes the impeller, it will strike the impeller in such a direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the stator’s over-running clutch to its shaft (Fig. 256). Under stall conditions (the turbine is stationary), the oil leaving the turbine blades strikes the face of the stator blades and tries to rotate them in a counter- clockwise direction. When this happens the overrun-
AUTOMATIC TRANSMISSION - 46RE
21 - 261
ning clutch of the stator locks and holds the stator from rotating. With the stator locked, the oil strikes the stator blades and is redirected into a “helping†direction before it enters the impeller. This circula- tion of oil from impeller to turbine, turbine to stator, and stator to impeller, can produce a maximum torque multiplication of about 2.4:1. As the turbine begins to match the speed of the impeller, the fluid that was hitting the stator in such as way as to cause it to lock-up is no longer doing so. In this con- dition of operation, the stator begins to free wheel and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
The
torque
converter
clutch is hydraulically applied and is released when fluid is vented from the hydraulic circuit by the torque converter control (TCC) solenoid on the valve body. The torque con- verter clutch is controlled by the Powertrain Control Module (PCM). The torque converter clutch engages in fourth gear, and in third gear under various con- ditions, such as when the O/D switch is OFF, when the vehicle is cruising on a level surface after the vehicle has warmed up. The torque converter clutch will disengage momentarily when an increase in engine load is sensed by the PCM, such as when the vehicle begins to go uphill or the throttle pressure is increased.
1 - APPLY PRESSURE 2 - THE PISTON MOVES SLIGHTLY FORWARD
Fig.255TorqueConverterFluidOperation 3 - RELEASE PRESSURE 4 - THE PISTON MOVES SLIGHTLY REARWARD
21 - 262
TORQUE CONVERTER (Continued)
AUTOMATIC TRANSMISSION - 46RE
DR
(4) Insert torque converter hub into oil pump. (5) While pushing torque converter inward, rotate converter until converter is fully seated in the oil pump gears.
(6) Check converter seating with a scale and straightedge (Fig. 257). Surface of converter lugs should be 1/2 in. to rear of straightedge when con- verter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle. (9) Fill the transmission with the recommended fluid.
Fig.256StatorOperation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL PUSHING ON BACKSIDE OF VANES 2 - FRONT OF ENGINE 3 - INCREASED ANGLE AS OIL STRIKES VANES 4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING AGAINST STATOR VANES
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the lifting device or work surface, the center of gravity of the transmission will shift when the torque con- verter is removed creating an unstable condition. The torque converter is a heavy unit. Use caution when separating the torque converter from the transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp edges, burrs, scratches, or nicks. Polish the hub and notches with 320/400 grit paper or crocus cloth if nec- essary. The hub must be smooth to avoid damaging the pump seal at installation.
(1) Lubricate oil pump seal lip with transmission
(2) Place torque converter in position on transmis-
fluid.
sion.
CAUTION: Do not damage oil pump seal or bushing while inserting torque converter into the front of the transmission.
(3) Align torque converter to oil pump seal opening.
Fig.257CheckingTorqueConverterSeating-Typical 1 - SCALE 2 - STRAIGHTEDGE
TORQUE CONVERTER DRAINBACK VALVE DESCRIPTION
The drainback valve is located in the transmission
cooler outlet (pressure) line.
OPERATION
The valve prevents fluid from draining from the converter into the cooler and lines when the vehicle is shut down for lengthy periods. Production valves have a hose nipple at one end, while the opposite end is threaded for a flare fitting. All valves have an arrow (or similar mark) to indicate direction of flow through the valve.
STANDARD PROCEDURE - TORQUE CONVERTER DRAINBACK VALVE
The converter drainback check valve is located in the cooler outlet (pressure) line near the radiator
DR TORQUE CONVERTER DRAINBACK VALVE (Continued)
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21 - 263
tank. The valve prevents fluid drainback when the vehicle is parked for lengthy periods. The valve check ball is spring loaded and has an opening pressure of approximately 2 psi.
The valve is serviced as an assembly; it is not repair- able. Do not clean the valve if restricted, or contami- nated by sludge, or debris. If the valve fails, or if a transmission malfunction occurs that generates signifi- cant amounts of sludge and/or clutch particles and metal shavings, the valve must be replaced.
If the valve is restricted, installed backwards, or in the wrong line, it will cause an overheating condition and possible transmission failure.
CAUTION: The drainback valve is a one-way flow device. It must be properly oriented in terms of flow direction for the cooler to function properly. The valve must be installed in the pressure line. Other- wise flow will be blocked and would cause an over- heating condition and eventual transmission failure.
TRANSMISSION RANGE SENSOR DESCRIPTION
has 3 primary functions:
The Transmission Range Sensor (TRS) (Fig. 258) †Provide a PARK/NEUTRAL start signal to the †Turn the Back-up lamps on when the transmis- sion is in REVERSE and the engine (ignition) is on. †Provide a transmission range signal to the
engine controller and the starter relay.
instrument cluster.
The sensor is mounted in the transmission housing near the valve body, just above the pan rail. It’s in the same position as the Park/Neutral switch on other transmissions. The TRS contacts a cammed surface on the manual valve lever. The cammed surface translates the rotational motion of the manual lever into the linear motion of the sensor. The cammed surface on the man-