why is my SC belt moving over?

[b18c ya]

My SC belt at the alternator is jumping one rib over toward the alternator. This is causing a very high pitched squeal.
Any Ideas as to why it is jumping over?
The Alternator/crank belt is fine.

[BoostedEX]

Check to see if the pulleys are aligned properly. Also check to see if the belt is tightened.

[96IntegraRS]

I have had the same problem... read on.

I had no trouble at 6psi (I have a B18B1 for reference, but the pulley principal is the same)

Anyway, I went to 9psi (with the stepper) and the belt would jump. I had to keep the idler I had on there (the big old aluminum one) which was too big; I couldn't tighten the belt enough.

Now, I'm at 9psi with the new plastic idler (smaller) and I can tighten the belt properly. It did jump about 1000 miles after I put a new belt on (obviously stretched). I now have the smaller idler, a tight belt, and it hasn't moved.

I thought that I was tightening the belt enough, but I wasn't. Don't tighten the hell out of it, but make sure that you have 1/4 of deflection per foot of belt... in our case, you should be able to "roll" the belt about 1/8 inch... these measurements are nothing but guesses... moral of the story is to keep that belt tight enough without ruining the blower bearings.

You also find alot of "missing" power when you tighten that belt up!

Chuck

[217gsr]

Mine used to jump because the bolt that held in the arm that allows the top idler pulley to move laterally wasn't on tight. I tightened that bolt down and haven't had a problem with it since.

[JRCivic]

Also make sure that your washers (there are in fact TWO of them) between the upper alternator bracket and the JR alternator stay bracket are installed properly... I have seen many rookies who have put one on either side of the stay bracket which in turn places the alternator in a bind... and the belt jumps around.

Both washers go between the OE bracket and the small stabilizer bracket (which looks like a 3" long strap with a small hole near each rounded end).

[b18c ya]

After working on it, and removing the tensioner pulley and belt you can see that the alternator is about 1 1/2 rib over toward the motor too far.
seeing as how there is no adjustment in the SC I'm guessing the alternator is off somehow.
Any more Ideas?
Thanks for the replies so far.

[zerokool59]

I had the same problem when i first installed my supercharger. make sure the rear bracket that goes from the back of the supercharger down to near the alternater is on tight . its a pretty thick flat metal strap .

[b18c ya]

I found the problem, there is a washer that goes between the alternator and alt bracket we had on the outside.

This did not fix my squealing though.