1G Timing belt off to one side

[er82]

I've been trying to figure out why the timing belt is offset to one side (6 bolt). I've tried a different cam gears, tensioner pulley and tensioner arm. The pulleys I have are NTN and GMB, are they OEM? The belt is more offset with GMB because its a fraction taller than NTN. Could it be the belt, crank sprocket, idler pulley, engine mount bracket? I've messed with the timing belt 3 times now. What are all OEM components should I order to get this fixed?

 

[linksys42]

Had the same problem a while back. The fix was a brand new oem tensioner arm. Bushing that rides on machined pin wears down over time.

 

[Vegas Smith]

Is it hitting anything in it's route?

 

[er82]

Had the same problem a while back. The fix was a brand new oem tensioner arm. Bushing that rides on machined pin wears down over time.

The two tensioner arms I tried, one had more play and the other almost nothing. But maybe the flat edges are worn. I can try a new one as they aren't that expensive.

Is it hitting anything in it's route?

The belt is right up against the edge of tensioner pulley and crank timing plate. When it's running, it smooth, not bouncing around or anything. I've attached a few more pics.

I got this motor with the car, that wasn't running. So, I don't know what's new or not, or OEM or not.

 

[SasaniFab]

This is normal guys.... the belt doesnt run perfectly sown center. The belt isnt as wide as the cam gears...

The belt is held against the trigger plate on the crank gear. The belt has some room to travel left to right....

 

[linksys42]

The two tensioner arms I tried, one had more play and the other almost nothing. But maybe the flat edges are worn. I can try a new one as they aren't that expensive.

The belt is right up against the edge of tensioner pulley and crank timing plate. When it's running, it smooth, not bouncing around or anything. I've attached a few more pics.

I got this motor with the car, that wasn't running. So, I don't know what's new or not, or OEM or not.

Take a look at this thread and I started back in 2008 on dsmtalk.
http://www.dsmtalk.com/forums/#/topics/186998?page=1

In the end what fixed it was a brand new OEM Mitsubishi tensioner arm that had no play or Slack in it.

 

[steve]

This is normal guys.... the belt doesnt run perfectly sown center.

I don't think that's normal. In my experience, normal is that the belt rides on the center of the sprockets. In the cases where it didn't I always found that the tensioner was worn and applied tension unevenly across the belt which cases the belt to walk in either direction depending on which side is loose. On my car I had to replace the mount and arm because the post for the tensioner arm was worn.

 

[SasaniFab]

I don't think that's normal. In my experience, normal is that the belt rides on the center of the sprockets. In the cases where it didn't I always found that the tensioner was worn and applied tension unevenly across the belt which cases the belt to walk in either direction depending on which side is loose. On my car I had to replace the mount and arm because the post for the tensioner arm was worn.

I dont have pictures to confirm, in the pics it appears like his belt is lined up too one side perfectly. When you install the belt and you are testing belt tension you spin the engine clockwise several times and by the belt should centers itself. I didnt read through the entire post, he said he replaced everything? Whenever I install a belt it always appears to be cocked to one side until the motor is turned over several times

 

[er82]

I dont have pictures to confirm, in the pics it appears like his belt is lined up too one side perfectly. When you install the belt and you are testing belt tension you spin the engine clockwise several times and by the belt should centers itself. I didnt read through the entire post, he said he replaced everything? Whenever I install a belt it always appears to be cocked to one side until the motor is turned over several times

Yes after rotating 6 full turns, the belt is already offset. It would seem to be the tensioner arm and engine mount bracket. I will try to get brand new ones and see if makes a difference.

 

[linksys42]

Yes after rotating 6 full turns, the belt is already offset. It would seem to be the tensioner arm and engine mount bracket. I will try to get brand new ones and see if makes a difference.

New tensioner arm will fix it. That is definitely not normal. If you run it like that the edge of the belt towards the engine will start to Fray badly and compromise the belt.

(Edit I just wanted to say thanks Steve for helping me out with that back in the day. I couldn't find any other post back then that knew what the problem was. Thanks again

I dont have pictures to confirm, in the pics it appears like his belt is lined up too one side perfectly. When you install the belt and you are testing belt tension you spin the engine clockwise several times and by the belt should centers itself. I didnt read through the entire post, he said he replaced everything? Whenever I install a belt it always appears to be cocked to one side until the motor is turned over several times

You can see in the pic that is zoomed in (below) that the belt is actually hanging off a little bit to the inside. It will get worse if he fires the engine up like that.

 

[SasaniFab]

New tensioner arm will fix it. That is definitely not normal. If you run it like that the edge of the belt towards the engine will start to Fray badly and compromise the belt.

(Edit I just wanted to say thanks Steve for helping me out with that back in the day. I couldn't find any other post back then that knew what the problem was. Thanks again


You can see in the pic that is zoomed in (below) that the belt is actually hanging off a little bit to the inside. It will get worse if he fires the engine up like that.

You had this issue and it was fixed by replacing the plastic bushing inside the tensioner arm?. So in other words the play in the arm is causing the tensioner pulley to allow for some radial movement and makes the belt wander. Ive never encountered this issue. Then again ive always replaced the arm when rebuilding an engine.

Can you feel any movement with the pulley torqued without the belt on? Im curious

 

[linksys42]

You had this issue and it was fixed by replacing the plastic bushing inside the tensioner arm?. So in other words the play in the arm is causing the tensioner pulley to allow for some radial movement and makes the belt wander. Ive never encountered this issue. Then again ive always replaced the arm when rebuilding an engine.

I didn't say in my posts to replace the bushing. If you ever actually look at the part you can see that it is molded to it and it's not plastic. You can't just replace the bushing. The whole arm assembly needs to be replaced.

 

[SasaniFab]

The aftermarket arm i purchased had an insert that could be removed. Your refering to the sleeve that the pin rotates on yes?

I understand, thanks for the clarification

 

[linksys42]

The aftermarket arm i purchased had an insert that could be removed. Your refering to the sleeve that the pin rotates on yes?

You can probably pry it out tearing the bushings up. But then you're going to have a hard time buying new bushings without buying the arm attached.

 

[SasaniFab]

You can probably pry it out tearing the bushings up. But then you're going to have a hard time buying new bushings without buying the arm attached.

I always considered those arms as something to be replaced when changing the timing belt, rock auto sells them for 16 dollars I believe. I dont have faith in anything close to 20 years old or more

 

[steve]

I had to replace the whole drivers side engine mount because the post that the arm swings on was worn.
It comes with a new tensioner pulley and tensioner arm.

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[pauleyman]

I'm kind of confused here. How does something with such little movement wear out? Ive logged 200k on a motor on the original part and it's fine

 

[steve]

Don't know. I don't think they are greased at the factory which can't help. I'll I do know is that they can and do wear out. Mine was shot at the 120k service.

 

[linksys42]

I'm kind of confused here. How does something with such little movement wear out? Ive logged 200k on a motor on the original part and it's fine

I figured that after years of pressure being applied to that Pivot Point by the centrifugal force of the belt at high RPM's the bushing on the arm or the machine pin on the motor mount bracket just wears out overtime. I guess some people are lucky and others are not.

 

[er82]

Thanks for everyones input! I got a new engine mount bracket. There still was some play in the arm, but less than the used one. Also, I noticed the front case gasket was sandwiched under the engine bracket. I think that may have caused to not sit flush and offset the pulleys. I trimed the gasket and installed the new bracket with ntn pulley, and it's all centered now.

 

[steve]

I'll have to remember to add the gasket to reasons why the belt might be running off. That will tilt the assembly.

 

[illestep3]

wow i should look into replacing that on mine , my belt doesnt ride center either, good to know