[Vwdiesel] '85 Jetta eating belts - solution

Shawn Wright swright at zuiko.sls.bc.ca
Wed Feb 2 10:44:35 EST 2005

I hope this is the solution...

After checking my '85 Jetta NA's alt belt last night, I noticed it was nearly 
gone again, this is about 6 months and 10-15k kms. Time to check if my 
eyes were correct in telling me that the pulleys were out of whack. 
Using an 18" straight edge across the flat of crank pulley and extending 
over water pump to alternator, I found this:
-water pump pulley inset approx 1.5 - 2.0mm from crank
-alt pulley was projecting past the crank pulley by 2-4mm

I don't think the alt pulley was the problem, but with the water pump so 
close to the crank, having the belt pushed 1.5 - 2 mm sideways was 
definitely a problem!

I shimmed the wp pulley by 1.5mm or so, and then ground the top left side 
of the alt mount down about 2-3mm, and shimmed the lower alt mount 
bolt. The effect of grinding the alernator mount seems to allow a bit of 
movement to finetune the alignment when the top bolt is loose, which is a 
good thing. I think I will use a straight edge (18" stainless ruler) from now 
on when installing this belt. I can now get the straight edge within .5mm 
across all 3 pulleys.

So if your engine is eating belts, grab a straight edge and take a look! It is 
not normal - my previous Jetta used to go 3-4 years on a single belt.

Shawn Wright
I.T. Manager
Shawnigan Lake School

More information about the Vwdiesel mailing list