New timing belt jumps teeth

[Blake]

Hi,
Backgound and car:
1998 Toyota Camry 2.2L
I purchased a timing belt and water pump kit online and the idler, tensioner and water pump pulley was bigger than the old ones.
I returned it and found one with the correct dimensions locally. The right kit has 2 springs with confusing instructions, but I tried both springs and have the same tooth jumping problem.

When turning the crankshaft gear to recheck that that timing marks are lined up, the belt jumps teeth.
I have a degree as an automechanic and have never run into this problem before especially on a car I replaced the timing belt in the past.
My next step is replace the crankshaft gear because there is about a .0015 inch, so the crankshaft rocks a very tiny amount.
Does anyone know what could be causing the belt to jump?
Also, does anyone know the spec on the tensioner spring dimension, 42mm or 46mm?

Thanks in advance,
Blaker

Topic

[Richard Kirshy]

Assuming the old timing belt didn’t jump teeth…
My first thought would be to check that the new belt is properly seating into all the gear teeth.
If the tooth count is off from the original or if the belt tooth outline / dimensions are even slightly different.
That can cause the belt to jump.

[Blake]

Thanks for the response but I physically counted the teeth on both belts.
I checked that the belt was sitting properly in every accessible gear tooth.
Yes, the old belt never slipped and was still in proper timing, however there was alot of oily mess in there and the old belt had some its fibers sprayed all over the bottom areas.
I did clean everything which is why I suspect it loosened up the crank gear because the grunge was keeping it tighter.

[Author]

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