-0000-NH

Soooo my girlfriend has this '90 100 which is in pretty good shape.. except for this recurring problem. The thing eats through alternator belts like a two-year-old through chocolate bars. Car had the wrong alternator on it when sh bought it.. thought that was likely the problem so I replaced it with the correct one, new. This helped, but hasnt solved the problem. The geared adjustment nut was missing with a lock nut and some washers in its place... I didnt think that would affect things much, but could it? I also thought about replacing the pully on the engine? Called around local scrapyards.. nothing out there for parts.

Anybody with an idea?

Avanthead

Re: How about the alignment of the pulleys??

Kneale Brownson

What belts are you using? If they aren't metric, you'll not have good contact with the pulleys.

rooster 2

then the pulleys should line up correctly. Take a good look under the car to see how the current belt is riding on the pulley. If the current belt looks like it is running properly around the pulleys, then the pulley alignment is probably good.

Using the correct tooth geared locking nut is crucial to getting the correct tension on the belt. When tightened properly, the belt at it's greatest distance between pulleys should only permit your fingers to rotate the belt barely 90 degrees at its midpoint length. If it is looser, the belt will slip and squeal. If it is tighter, then the extra tension will wear out the bearings in the alternator pulley.

Also, use good belts made by Gates, Goodyear, or Continental. Don't waste your time buying cheapie off brand belts. They don't hold up. Autozone's cheapie line of Kelly Springfield belts are poor. They don't break, but require retighening about every three months because of stretching. Stick with the better belts.

boxerfan

Then bought a Conti... no problems since. Cheap belts are complete crap these days IMHO.

RussB

Obviously, Audi dealers sell it. Also, aftermarket distributors (IMC, I think. Otherwise, Worldpac) sell it as well, for not much more than a dollar or two. Do an on-line search for resellers.

BTW, Audi used a variety of alternator pulleys. Some consist of two dished thick sheet metal stampings, while others are one-piece metal castings. I've found two different diameters, as well: approx 2 inch and approx 2.5 inch. I've not found a pattern of which pulley was fitted to which model.

Here in South Florida, with lots of traffic, frequent fan and after-run pump operation, and almost continuous operation of the air conditioner, I've opted for the smaller diameter pulley on my 88 5000CSTQ to keep the alternator rpms up. I also retrofitted a 110 Amp alternator. (The car's stock alternator was 90 Amp.)

The only belt that I recommend is a Conti.

RussB

As with many things Audi, this procedure is five times more complicated and requires more tools than it should.

Part nbr 034 903 555 B includes the toothed adjustment nut and its bolt with a 13 mm hex head. I think that the adjustment nut's hex is 19 mm (or 21 mm?).


The procedure to adjust the alternator belt that I follow on my 1988 5000CSTQ is:

1. Remove alternator cooling duct

2. Loosen 5 bolts/nuts in this order:

o 13 mm bolt head that runs through toothed adjustment nut

o 13 mm bolt head that forms pivot at engine block for small sliding bar

o 17 mm nut that fastens round support tube from AC compressor to small sliding bar

o 17 mm bolt head at front of alternator pivot

o 17 mm bolt head at rear of alternator pivot


To tighten, I turn the toothed adjustment nut with a 19 (or is it 21 mm?) box wrench until the belt is good and tight, and while continuing to use this wrench to keep the belt tight, I tighten in this order:

o 13 mm bolt head that forms pivot at engine block for small sliding bar

o 17 mm bolt head at rear of alternator pivot

o 17 mm bolt head at front of alternator pivot

o 17 mm nut that fastens round support tube from AC compressor to small sliding bar

o 13 mm bolt head that runs through toothed adjustment nut

Reinstall alternator cooling duct.

-0000-NH

Went through all kinds of alignment adjustments before realizing it was the wrong alternator. New one seems to line up perfectly. Wondering if there is a burr or something on the engine pully, or maybe its warped somewhere?

-0000-NH

Actually, the last one to break was from Autozone, but had audi logos on it. Although it lasted much longer [with the new alternator] it still eventually snapped after about a month.
I dont get it.