Annoying and persistent belt squeak

[iTurbo]

I have a very annoying and persistent belt squeak on an '86 GLH Turbo. It is coming from the alt/water pump belt. The car has been fitted with a rebuilt 90 amp Nippondenso alternator, smooth water pump pulley, and new bracket bushings from PolyBushings.com. (common block water pump/alternator/belt setup).

I was able to make the squeak go away for about a week after installing a new belt, but now it has come back. The belt doesn't screech like it is too loose, but makes a constant chirp-chirp-chirp noise that I can't seem to do anything about. I adjusted the metal sleeve in the alternator pivot point to get all the pullies to line up perfectly. I've tried adjusting the tension more/less without success.

I brought the alternator in to NAPA today and had it bench tested. It passed but it was putting out about 15.4 volts which they say is rather high. About the only idea I have right now is to remove the water pump pulley and sand it with some emery cloth to clean off any belt glaze and install a FWDP ground wire kit.

Anybody have any other ideas?

[acannell]

I have a very annoying and persistent belt squeak on an '86 GLH Turbo. It is coming from the alt/water pump belt. The car has been fitted with a rebuilt 90 amp Nippondenso alternator, smooth water pump pulley, and new bracket bushings from PolyBushings.com. (common block water pump/alternator/belt setup).

I was able to make the squeak go away for about a week after installing a new belt, but now it has come back. The belt doesn't screech like it is too loose, but makes a constant chirp-chirp-chirp noise that I can't seem to do anything about. I adjusted the metal sleeve in the alternator pivot point to get all the pullies to line up perfectly. I've tried adjusting the tension more/less without success.

I brought the alternator in to NAPA today and had it bench tested. It passed but it was putting out about 15.4 volts which they say is rather high. About the only idea I have right now is to remove the water pump pulley and sand it with some emery cloth to clean off any belt glaze and install a FWDP ground wire kit.

Anybody have any other ideas?

welcome to the club! for the last couple years ive been squeak free but I vividly remember a period of time where there was a squeak that needed to die

what made it worse was that it was a brand new alternator...

turned out either the alternator was defective or I had over tensioned the belt and ruined the alternator bearing. I had to swap the new alternator for another one and the problem went away up to this day

if you spray the belt with a little water while its squeaking, does the squeak stop?

[iTurbo]

Thanks for the suggestion, I will give that a try. I have a NAPA rebuilt 120 amp Nippondenso alternator on the way so I will be trying that out as well. It may actually be bearing noise but sometimes it's just really hard to tell.

I did remove the water pump pulley. I cleaned it with Brakleen, wire wheeled it on a bench grinder, and then sanded the outer circumfirence with emory cloth down to bare steel. I cleaned the crank pulley and alternator pulley with some Brakleen as well. The belt only has maybe 100 miles on it. I just now got done putting it all back together and it still squeaks just as bad as before.

I also installed the FWDP ground wire kit and that definitely made an improvement to the charging voltage. It is noticeably higher on the cluster gauge and my gauges are no longer going apeshit either. Now with all electrical items on, it just ever so barely makes the voltage needle tick with the blinkers whereas before it was all over the place. Much more stable voltage now.

[iTurbo]

I also am buying a new alternator isolator bracket from PolyBushings.com. The one on the car is fairly soft and has a big crack in it.

http://www.polybushings.com/pages/altIsolator.html

[shackwrrr]

the Nippon alternators have a different mounting depth. I had to adjust mine with washers to stop the squeal.

[iTurbo]

I finally got it to stop squeaking. As it turns out it was the polyurethane pivot bushings that go in the alternator/AC bracket. Not the bushings themselves, but the steel bushing sleeves were too long. They were long enough that it would push the larger steel sleeve pressed into the alternator case out of alignment every time I tightened the pivot bolt. I went back to a decent set of stock rubber bushings/sleeves and readjusted the alternator pivot sleeve and finally got it to stop. No more noise!