I just finished replacing the alternator belt on my '92 XJ6 (not an easy job) and am greeted by a high-pitched squeal coming from the front of the engine when I accelerate. I read in another post that the crank damper can make this kind of noise and must be rebuilt or replaced but slipping belts can also make noise. I think I got the three belts tensioned correctly but maybe I didn't. How does one tell if the squeal is coming from a belt or the damper? How many miles do crank dampers usually last?

 

Hello,

I replaced mine at about 157,000 miles. I kept the old one and plan to send it out to have as a spare.

When mine failed it started to intermittently squeal at star up, and progressively got worse. That squeal is not very "Jag-like" is it? I don't ever remember hearing any squeals from belts on this car.

I found a used one with 60,000 miles on it for $75.00 (new, this part is about $900.00). I'm currently near 177,000 miles and it seems fine.

 

Well if you have just finished replacing a belt and then you get squealing then conventional logic would suggest that the belt is the problem.

Try spraying the belts & pulleys with Amorall or other similar product. If the belt is squeaking this will often make it stop or at least reduce. Only a temporary solution but may help diagnose.

 

Well, after checking the tension on the new alternator belt again I decided it could stand a little more tightening so that seems to have eliminated the squeal. It seems the tension on that belt is critical.