My car is a AE92 corolla with a 4A-F engine, although other engines are completely different I imagine that many of the steps are close to identical.... except for say, cars with a Timing Chain like the Nissan SR20 and a bunch of others.
At first you need room to access and work on the area, so remove the tyre (i think only for fwd cars) and some of the protective plastic pans that are along the side and bottom of the car. this is a pic where the plastics have been removed. ps. other things i moved were the air intake piping as well as the water bottle.
The next step requires you to set the engine at TDC, this can be done a number of ways, me and dad just did it by feel and checking that the distributor was at the appropriate position. on the list of things to get out of the way are also the various belts. (position of these belts does not matter so just undo the bolts on the (Eg.) alternator and move it into position so that the belt is loose enough to slip off.
This is the pulley on the crank, in the picture the bolt is already off but we found this to be fairly hard to remove without turning the engine (obviously). so we ended up putting the car in gear and holding everything in place with the brakes in order to get the nut off. after that you need to get a puller (VERY USEFUL) and use the little holes in the sides to pull the whole thing off the crank shaft(dont know if this is the proper name but the end bit is part of the crank...)
Once this is off you can get at the cam covers; for my engine i had to take off the valve cover in order to get the top part (theres 3) off. at this stage we also decided that the gasket and the three seals on that the screws that hold the valve cover in place were also due for a change so we got these.
Heres the pic where everything is off..the only thing left to do here is to loosen (or remove) the tensioner so that you can get the belt off. but before you do this you have to STOP! this is a crucial part of the service, you have to make sure that youll be able to get the new belt in the exact same position (tooth for tooth) and also that the position of the wheels (cam/crank) will not be changed while the belt is off. on my engine there are some very useful factory markings which made life fairly easy but i still made many of my own. one useful thing is to mark two parts where the belt and wheel/s and then when you put the new one on make sure there are exactly the same number of teeth between these marks as there were with the original.
As you can see here the belt is off and notice the allen key in the cam wheel hole which actually slots into a hole in the head so that you wont lose position! the bottom sprocket was also marked so that we could have it in the original position when fitting the new belt.
This is a picture of the old belt, you can see that there are significant cracks in the belt where the teeth are and this is a tell tale sign of a worn belt (this one had gone through 150K without a change!). at this stage you can simply refit the new belt but me and dad wanted to change the cam and crank oil seals while we were at it so for this you need to remove the top and bottom sprocket.
When we were removing the bottom sprocket it was stuck and we eventually broke a part of it off (NOT GOOD). it was still stuck though and after 30 minutes of scrachin our heads i had the brilliant idea of getting a drill and drilling some holes into the sprocket so that we could get it off witht the puller then go on and try to get a new one at the wreckers or whatever. it worked a treat and the new one only cost us 25bucks
To get at the cam seal its a bit easier, just grap hold of the cam and get the nut off the end with another wrench. the seals themselves come off by yankin at them with a screwdriver and are put back in place by GENTLY hammerin them back into place. after that its a simple matter of puttin everythin back (new for old where possible) and taking your time doing that so that you dont end up with any spare screws.
All together i was very happy with the outcome. i learnt a fair bit through the experience and me and dad doing it saved me a lotta money too. i got quoted 240 for just the timing belt change and 70bucks extra for the seals... DIY cost= 200 this includes belt, cam/crank oil seals, gasket, bottom sprocket, valve cover screw seals, a drill, 2 drill bits, threader (the thing that makes the thread for the screw to go through after you drill it), puller and a can of WD40. if you have any questions on anything or ur after more details just post them up and ill try to get back to you ASAP.
Nice article dude, I may have to do this sometime.
