Club 80-90 Forums

Reading in Brickyard about bottom pulleys on AAZ engines working loose. They say that VW realized they had a problem and modified them after a couple of years. Anyone know any way in which you can tell if yours has been modified? Short of a major strip down!

Not sure how to tell, but advise either keep checking it is tight and change it at next cambelt change, or if really worried just swap it, bolt is a few quid from VW, I'm changing mine with cambelt sometime soon.

you could always wip the bolt out and put some thread lock on it ????

The modified bolt has a round "pip" on the 12 sided head, it`s quite obvious when you see one. It`s a stretch bolt, so needs to be tightened up as per VW spec, which can be a bit hard, trying to stop the motor from turning over while you do it You need to lock the flywheel with somthing while you heave on a socket and bar on the bolt. I would be inclined to Loctite it as well, belt n braces

If you`re doing it, give the bottom pulley a wobble before touching the bolt, to see if you can move it, if you can, buy a new lower cambelt sprocket (£25) and bolt (£2) before starting the job, hopefully it won`t have worn the location slot in the end off the crank

Replacing the bolt alone is a waste of time and money, new pulley and bolt every 60k and it will never be a problem. The problem was never fixed until they fitted tdi cranks but you will be very lucky to find one. Bolt should be oiled, no thread lock and tightened to 90nm + 90 degrees, once tightened do not touch it agian until next belt change.