BobS!

I have worn cam gears. I assume most 928s cam gears are worn to some degree. What is the issue. How bad is bad? Is re-treatment adequate?

My reason for pulling parts off the engine ... looking for the cause of the random timing belt light illumination. The belt tension appears to be right with a cold engine.

88 S4 5spd 105000mi

Big Dave

Can you post a picture of your cam gears?

Once the protective coating is gone, the surface of the gears wear more rapidly, resulting in a "dished" appearance to the cam gear teeth which can cut into the belt.

AO

Some will say any amount is bad. Since you have a 32-valve Interference engine, I'd tend to think that way too - Just ask BigDave what it's like to have a timing belt failure.
If the coating is just starting to come off is places, you can get them recoated. Don't know the longevity/efficacy yet. If they're starting to dish, replace them.

BTW, If you end up replacing them, I'd be interesting getting your oil pump and crank gears as I'm trying to upgrade to the round tooth belt design. I've got the cam gears, but not the others. I can run with less than optimal gears as my engine is not an interference engine. Ahhh... it's sometimes nice to be an OB!

Jim R.

Bob- If they look worn, just replace them or get the re-coated if the metal is not worn. It is just not worth trying to save $200 and risk damage to the top end ($$$$).

Andrew- I have my old crank and oil gears. They are in decent shape, but not perfect. When I saw my worn cam gears, I decided to replace them all and start fresh. The gears are yours if you want them-just pick up the shipping.

Jim R.

AO

Jim. Sending you a PM.

Glen McCartney

BobS, sent you a PM

BobS!

OK, so I replace the cam gears. I got on the big 3 web sites. If I replace every item becasue it is not new, where does it end?

There are tooth gears (4?), roller bearings, Timing Belt Lower Idler, Timing Belt Tensioner IDLER, Timing Belt Tensioner Roller, Bearing for lower guide roller,Lower guide roller 2 bearings ... Tensioner parts, a given ... then there is the belt.

AO

No need to replace the gears unless they are worn beyond use. And depending, depending ont he year of your car, you may be able to get away with marginal gears (like me) and not have any "issues". If the gears are not dished, you can have them recaoted for a fraction of the cost.

Big Dave

Here's a link to some cam belt gears, including shots of some badly worn gears:

http://www.928oc.org/928oc_michigan/tbelt7.html