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Exhaust cam gear shifted by a tooth

98EclipseGSXLincoln

Probationary Member
9
1
May 27, 2022
Lincoln, Nebraska
My exhaust cam gear shifted slightly counter clockwise right as I took my timing belt off. It's a 4G63T and I'm trying to figure out the proper way to set it back. I checked in the documentation and can't get a good idea of what to do. After searching, some say with similar engines that you can just rotate the gear however far back until they line up again and put the belt on. Not knowing a whole lot about the possible consequences of this, does this sound right?

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DSMPT

DSM Wiseman
2,209
1,801
Jun 12, 2014
Japan / Mexico, Arizona
If you remove the timing belt with the cylinder #1 at TDC, the exhaust cam would be pushed back counterclockwise by a tooth is normal. That's even mentioned in the factory service manual. But do not rotate the cams without the timing belt installed. You may regret by ending up to bend valves.
 

98EclipseGSXLincoln

Probationary Member
9
1
May 27, 2022
Lincoln, Nebraska
If you remove the timing belt with the cylinder #1 at TDC, the exhaust cam would be pushed back counterclockwise by a tooth is normal. That's even mentioned in the factory service manual. But do not rotate the cams without the timing belt installed. You may regret by ending up to bend valves.
So if I wait to move the cams until the belt is back on, they will still remain a tooth off I'm assuming. Is there a proper way to re align them without risking valves?
 

dwb

Proven Member
359
191
Sep 9, 2021
Broomfield, Colorado
That's normal when removing the belt. Just put a 17mm wrench on the cam bolt and rotate it a tiny bit clockwise so you can get your belt on with the marks aligned (and then clamp your belt to each gear so the belt doesn't slip off). Just be careful not to rotate either cam any further than a tooth or so if your crank is TDC or BDC. If you want to be extra cautious, rotate your crank away from TDC or BDC before moving a cam.
 

99dsmer4g63

Proven Member
173
86
Sep 20, 2022
Shippensburg, Pennsylvania
Sounds like you took your timing belt off without a proper game plan on how to correctly re install it.


This is all you should need to understand how to install the belt.

-Daniel
 

DSMPT

DSM Wiseman
2,209
1,801
Jun 12, 2014
Japan / Mexico, Arizona
So if I wait to move the cams until the belt is back on, they will still remain a tooth off I'm assuming. Is there a proper way to re align them without risking valves?
You need to advance a tooth when you put back the belt. That's won't cause problem. But don't rotate many teeth. Please refer the FSM.
 

98EclipseGSXLincoln

Probationary Member
9
1
May 27, 2022
Lincoln, Nebraska
Sounds like you took your timing belt off without a proper game plan on how to correctly re install it.


This is all you should need to understand how to install the belt.

-Daniel
You might just be right on that one. The quote to have a shop do it was too high for me. So I tried learning what I could and tackled it like I have everything else, which is to just do it. Sometimes it gets me in situations similar to this. Thank you for the link.

-Also Daniel
 

99dsmer4g63

Proven Member
173
86
Sep 20, 2022
Shippensburg, Pennsylvania
You may want to invest in the 3 piece timing belt tool kit. Makes the install much easier. Really the only way to properly tension the happy face pulley as well IMO.

Also the faq shows a different way but I like to zip tie the timing belt to the cam gears while installing the belt to help hold everything together until I’m ready to rotate the motor by hand.

-Daniel
 

dwb

Proven Member
359
191
Sep 9, 2021
Broomfield, Colorado
Here's how mine looked. A lot easier, but not necessary, with the engine out of the car. It gives you a nice visual of the clamps and where the marks, including the crank, should align. I've done it many times inside the car without any special tools.
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98EclipseGSXLincoln

Probationary Member
9
1
May 27, 2022
Lincoln, Nebraska
Here's how mine looked. A lot easier, but not necessary, with the engine out of the car. It gives you a nice visual of the clamps and where the marks, including the crank, should align. I've done it many times inside the car without any special tools.
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This is a great visual. Thank you.
 

99dsmer4g63

Proven Member
173
86
Sep 20, 2022
Shippensburg, Pennsylvania
If you have the original 7 bolt in the car you need to follow the 93 instructions in the link I posted. The timing mark for the crank is different than the one posted in the picture above.

Also the tensioner pulley I believe rotates the opposite way. It will only rotate one way putting tension on it without interfering with a part of the front case so should be self explanatory.

-Daniel
 

pauleyman

DSM Wiseman
8,438
2,954
Nov 19, 2011
oklahoma city, Oklahoma
You guys are getting the OP all nervous.
OP you aren't in a situation. This is normal. when you're ready you just put the belt on and rotate the cam forward that one tooth. If you need to rotate cams during this job you just have to make sure none of the pistons are at the top. I assume you had the crank lined up. That would make 1 and 4 at the top. If the crank is move a few degrees away from the mark then no pistons are at the top. No problem. Just move it back when you're ready to put the belt on.
BTW those huge clamps are awesome. On the car office binder clips work great. I keep a pair with my timing belt tools.
 

chrysler kid

20+ Year Contributor
2,610
579
Dec 20, 2002
Mckinney, Texas
Just use a wrench to turn it back to where it was so you can put the belt across it properly. Once the belt is lined up across them so they are at top dead center; zip tie the belt to the cam gears so that when the cam gear tries to move like that again; that they belt doesnt slip off and your actually set timing off by a tooth

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curt-s

Supporting Member
1,611
381
Dec 21, 2008
Winnipeg, MB_Canada
I use a set of 17mm spanners and squeeze them together with one hand while I lay the belt over with the other, then zip tie as above.
You can get 4g63 cam alignment tools on aliexpress even nowadays, of all places, provided you're willing to wait the 6 weeks. However I cannot speak to their accuracy on tooth alignment. Perhaps I should take the plunge though I don't really need one.
 
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