[Turboeagletalon]

you got to understand the exaust cam is supposed to be like tooth or in apperence a haft tooth of the picks above are right.


www.vfaq.com timing belt 1g read it

 

[oldman]

That is at least one tooth off like steve said, there is no question about it assuming the crank is lined up. dsmbuilder and Luni420 are right, when installing the belt prior to tensioning, the exhaust gear needs to be rotated one tooth CW, they should look one tooth off (opposite way of the picture) before tensioning and 100% lined up after properly tensioned.

THERE IS ABOSOLUTELY NO DOUBT ABOUT THIS. When stevep say it's off, it's off.

 

[MindBlowin03]

dsmbuilder and Luni420 are right, when installing the belt prior to tensioning, the exhaust gear needs to be rotated one tooth CW, they should look one tooth off (opposite way of the picture) before tensioning and 100% lined up after properly tensioned.

That is not always true. Ive done three timing belts and two needed to be 'pre-loaded' and the other didnt.

 

[oldman]

That is not always true. Ive done three timing belts and two needed to be 'pre-loaded' and the other didnt.

If the final result looks like the OP's picture, it is off. I've always had to preload.

 

[White91GSX]

looks like the exhaust cam needs to be set back one tooth. That should make it perfect. IF the crank sprocket is in time, than the exhaust is definetly a tooth off.

ya thats what i was ognna say the exhaust is a tooth off

 

[Turboeagletalon]

no it's not. your supposed to put two 17mm wrenched as on the cames tun the so the timming mark line up with the top of the head. then put the belt one the intake cam. then release the exaust so it turns, it will be about one tooth, put it on. now the put the timming belt on the oil pump in a maner so when you go to put pull the belt tight for the crank pulley, the timing marks line up on the oil pump. this will inshure carect tension between the crank and the intake cam. now put the belt over the tensioner pulley
pull the tensioner pin. onless you really fucked with it you shouldn't even need to mess with the tensioner pulley

 

[White91GSX]

no your wrong BEFORE you put the timing belt on the exhaust should be one tooth behind and it will straighten its self but his belt is alreayd on therefor he is a tooth off

 

[Turboeagletalon]

no your wrong BEFORE you put the timing belt on the exhaust should be one tooth behind and it will straighten its self but his belt is alreayd on therefor he is a tooth off

what ever it alost cause to argue with you. go blow your shit up. i bet here motor starts just fine

 

[oldman]

what ever it alost cause to argue with you.

There is really no arguments here, you'r incorrect, the marks must line up after exactly as shown in VFAQ.....unlike the OP's original pictures.

go blow your shit up. i bet here motor starts just fine

Being one tooth off will not prevent the motor from starting up nor will it "blow your shit up". If you're just going to throw out non-sensor because someone disagrees with you, please stay out of the discussion. This issue is too important to be ignored, many people make the same exact mistake like myself on my first timing belt job, I ran my car one tooth off for an entire year without even knowing it. Bottom line, if you have to question whether marks line up, they're off.

 

[stevep]

It's not that hard to make sure everything is spot on while your installing the belt. As you put the belt on each sprocket turn it and make sure it doesn't move without the others moving too. I usually back up the sprocket part of a tooth to get the belt on and then pull it tight checking to make sure the timing mark lines up and move to the next. The only slack then that will be left is between the crank and exhaust the tightening the tensioner pully won't cause anything else to move.

After doing the 6G72 belts the 4G63 belt is a breeze.

Steve

 

[op712]

( I know this is an old thread, but a question still arises: ) Where he used the larger drillbit, thus causing the tension pulley to be more drawn in towards the right, wouldn't this cause the marks on the exhaust cam sprocket to be more pulled forward to the left, thus going out of line with the intake marks?

 

[stevep]

( I know this is an old thread, but a question still arises: ) Where he used the larger drillbit, thus causing the tension pulley to be more drawn in towards the right, wouldn't this cause the marks on the exhaust cam sprocket to be more pulled forward to the left, thus going out of line with the intake marks?

No.

The belt doesn't stretch to speak of so the relationship between the sprockets is maintained if there wasn't slack between them when the belt is tensioned.

The only slack in the belt when you correctly install it is between the crank and exhaust cam, and that's what adjusting the tensioner pulley takes up. Once that slack is gone any additional rotation of the tensioner pulley causes the tensioner arm to move which loads the auto-tensioner and belt. If you had improperly installed the belt the timing marks would shift as soon as you started tensioning the belt.

The clearance between the tensioner arm and the body of the auto-tensioner changes the range of motion that the tensioner arm can move but it doesn't change the timing marks.

 

[op712]

HI again - thx for the help on this .. makes excellent sense.

Another question: the timing belt sprocket - does that have to be pulled off with a puller, or does it just slip off the crankshaft after removing the end bolt so one can get to the balance belt assembly?

(my first experience with the 4G63 - even though I've done DOHC engines before with belt changes ..)

thx-Op712

 

[stevep]

The crank sprocket slides off but it's not unusual for it to be stuck.

 

[op712]

Thx for the help on this, for I'm getting a '90 Ply RS Turbo in very good condition. Body needs a bit of help (a push-in goose egg dent on the passenger quarter panel that's an easy pushout, and numerous door dings) with some body work and repaint, the interior looks almost new-driver's seat with very little entrance wear, but the classic headliner falldown-needs to be recovered or replaced.

Motor runs super smooth along with the turbo, BUT as with any vehicle with high mileage (161k) is to get the thing home and immediately do the belts, for I heard plenty of horror stories in these forums of busted or mistimed belts that suddenly destroys the 4G63 motor.

Big one that I recently heard is that two guys doing a belt change on a 4G63: Got the belts in and one guy with the wrench begins to turn the motor around to seat the belts, but noticed that the crank was suddenly horribly hard to turn with the wrench, yet he kept turning to do the six revolution requirement. The other guy asked him about the stiffness of the wrench and immediately knew that every valve was bent due to the belt wasn't positioned correctly - and just by doing the wrench turn, did the number on the valves.

Thus with hearing this begins a tip to all: If you do the socket wrench turn to chek belts, if you feel any sudden resistance in the wrench, you got a valve in the way of a rising piston and they are meeting in an unfortunate and forbidden area - being interference motors.

thx-Op.712