Timing belt won't track straight

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spiderman2000

Timing belt won't track straight

Post by spiderman2000 »

Ok, I could really use some insight. I just finished replacing the timing belt following all the instructions in the manual. I centered the belt on the gears/tensioner. Before buttoning everything up I turned over the engine 2 complete revolutions by hand. Everything looked and sounded fine. Started her up and the belt will not track straight. It wants to run against the back lip of the intake cam gear and on the back side of the tensioner. Doing this causes the belt to rub on a raised portion of the block between the tensioner and the exhaust cam gear. What am I doing wrong ???? I have heard that this may mean that the gears need to be replaced. Say it ain't so.... I am ready for some up time, instead of all the down time. :?

FWIW I did also replace the tensioner bearing when I replace the belt.
So Cal Mark

Re: Timing belt won't track straight

Post by So Cal Mark »

are you sure the tensioner assy is seated flat against the block?
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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: Timing belt won't track straight

Post by TulsaSpider »

Did you figure it out? Kayce (on Facebook) said something about the gears not being level, but there's no adjustment.
Just checking up!
1978 Spyder 1800 make that 2L! Finally making real progress!
spiderman2000

Re: Timing belt won't track straight

Post by spiderman2000 »

Mark

Checked the tensioner and everything is flat and square against the block. None of the gears appear to be worn to cause the belt to not track correctly. I have even gone as far as removing the belt and realigning everything but nothing seems to work. Is there anything else that I should be checking?

If anyone else has any ideas please don't hesitate...
So Cal Mark

Re: Timing belt won't track straight

Post by So Cal Mark »

did the old belt track straight? Possibly the cords in the belt weren't laid straight when it was built.
spiderman2000

Re: Timing belt won't track straight

Post by spiderman2000 »

It appeared that it had rubbed or not tracked straight at some time in the past and due to the age of the belt it needed to be replaced. I figured it was the tensioner and belt causing the issue so both were replaced. After all the searching I've done on this forum I have yet to find any information on anyone having these kinds of issues, or gear issues. I just figured that since the belt and the tensioner bearing are the weak links that the gears would not be an issue.


Frustrated :evil:
mdrburchette
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Your car is a: 1972 Fiat 124 Sport
Location: Winston-Salem, NC

Re: Timing belt won't track straight

Post by mdrburchette »

Is it possible the belt was installed too tight? Usually you'll hear a squeaking noise if so, but the belt could "walk" on the cam wheels.
1972 124 Spider (Don)
1971 124 Spider (Juan)
1986 Bertone X19 (Blue)
1978 124 Spider Lemons racer
1974 X19 SCCA racer (Paul)
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So Cal Mark

Re: Timing belt won't track straight

Post by So Cal Mark »

worn sprockets are very common, especially if they are plastic
spiderman2000

Re: Timing belt won't track straight

Post by spiderman2000 »

Mdrburchette,

Don't think the belt is to tight. The belt is riding on the spring tension of the tensioner. I have added no other force or tension to it. I rotated the engine over by hand at least 12 times and it was tracking straight. It wasn't till I started her up that it moved and started rubbing on the block.

Mark,

As for the gears wearing out, the only plastic one is the auxillary gear. It looks good, but I just order a new one and will replace it whether it needs it or not. How common is it for the metal gears to wear ?

:(
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TulsaSpider
Posts: 1547
Joined: Tue Apr 29, 2008 7:33 pm
Your car is a: 1978 Spyder 124 2L
Location: Tulsa, Ok

Re: Timing belt won't track straight

Post by TulsaSpider »

Jeesh what a strange problem! It can't be too many things. Good luck!
1978 Spyder 1800 make that 2L! Finally making real progress!
ventura ace

Re: Timing belt won't track straight

Post by ventura ace »

spiderman2000 wrote:Mdrburchette,

. . . The belt is riding on the spring tension of the tensioner. I have added no other force or tension to it. . . . :(
I'm sure you realize that you need to tighten the tensioner bracket nuts after the spring is allowed to settle into the 'home' position, . . . right? It's not like the Serpentine belt on a modern car where the tensioner belt is constantly re-tensioning the belt. If the tensioner bolts aren't tightened down, then I could see how something weird could happen -- the worst of which would be the belt slipping a few teeth. I'm guessing you did this correctly, but need to ask anyway.

Alvon
spiderman2000

Re: Timing belt won't track straight

Post by spiderman2000 »

Alvon,

Guess I was not very detailed in my explanation. Basically I tightened it in the loose position but the belt on loosened the tensioner so that the spring would tightened the belt then tightened all the bolts.
ventura ace

Re: Timing belt won't track straight

Post by ventura ace »

spiderman2000 wrote:. . . loosened the tensioner so that the spring would tightened the belt then tightened all the bolts.
Good. Sorry, but had to ask and cover all the bases. Now, just to clarify: the tensioner bracket should be flat against the engine block (no washer behind it anywhere), The bearing goes on next -- being sure that it is the correct bearing. Right? The earlier smaller engines had a narrower bearing, which might not support the wider 2.0L belt correcly. Then there is a bearing seat that goes on, with the smaller diameter nestled inside the bearing ID. Then a thick flat washer, a lock washer, and then the big nut.

You suggested that this problem may have been there previously. A collapsing plastic aux shaft gear might be pushing the belt backward. I wonder if the crankshaft cog gear may have been changed out with the wrong part at one time. I see in the parts book that a change was made after 1976 for this gear. I don't know the difference in the post '76 gear -- just throwing that out there for question.

Mark mentioned that the belt may be defective. You might want to try taking it off and flipping it around the other way to see if it still moves backward.

Hope you find the answer.

A
So Cal Mark

Re: Timing belt won't track straight

Post by So Cal Mark »

ohh, the metal gears do wear, including the crankshaft sprocket. There are two different crank gears and the spacing is different between them. If the wrong one is on your crank that could cause the problem. I'd use a straightedge and see if all of the gears are in line with each other
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Tappy
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Your car is a: 124 spider 2000 1979
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Re: Timing belt won't track straight

Post by Tappy »

ok i digg up this post becouse i have the same problem .... spiderman 2000 did you solve the problem yet ? and if so what was causing it ?
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