checked my belts today because they were making weird sounds after i tensioned them and discovered that on one side my balance belt is deeesstttroyyedd. one ide is perfectly fine but the other the teeth are worn down to nothing. there was all sorts of rubber dust/foamish stuff in the airbox and stuck to the belt cover.

what would have caused the teeth to die like that?

 

Frozen bearing on the tensioner pulley? Tensioner twisted the wrong way causing it to drag on something?

 

Is it the side that contacts the idler/roller? If so, the idler may have seized and friction over time caused the disintegration of the belt.

 

the roller turned out to be fine, it spun without making any noise and was smooth for a loonnnggg time that it spun.

it is the inside of the belt that wore.

 

Tension too tight and/or a siezed tensioner. Did your car shriek practically because the balance belt was soo tight?

 

it made the normal whine for a while after i tensioned it, not toooo loud but just right.

and then about a week ago it sounded lopey at idle, not unlike an old SBC with a race cam. and then when you got close to the engine it sounded like a busted bearing. and when you stood on the gas it would lope faster and faster and actually sounded pretty cool. but now i see why it was so facked

 

Has the tensioner spun on the bearing? I've seen a slightly over tensioned belt melt the tensioner until it separated from the bearing. Bearing was fine, but the roller had separated from it.

 

the pulley spun fine...

 

Maybe then it's simply a bad belt ???

 

less than 15k on entire engine...

 

Spencer,
Not sure about the teeth on the belt (sorry) but I thought that the hose from the belt cover to the air cleaner box was supose to be blocked off as per a Porsche TSB. Something about the intake actually pulling dirt and grit into the belt area. I have the Porsche blockoffs on my '88 944S, look like rubber caps.
Could your pulley washers/belt retainer flanges be on the wrong side of the pulleys??
Glenn

 

I've had that happen a couple times for a couple reasons...

1) internal timing cover bolt backed off... killed the balance belt.

2) frozen roller- spun fine, nice and smooth, but it just needs a little bit of a catch. as I understand it, with those sealed bearings, if they spin for a long time, they're bad. replace em.

 

Do you have the tensioners on wrong? Like the cam belt as the balance belt tensioner and the balance belt tensioner as the cam belt?

 

no...im just guessing the belt was too tight. and died

 

Thanks. That's really reassuring for me when I have a belt about as tight as a new timing belt