SC Belt jumping ribs

[newgsrdriver]

So a few weekends ago I was launching the car, and my alternator belt flew off mid launch and turned inside out.

I popped it back on, it did it again.

So I went back and noticed that my SC belt was off a rib. It was on 3 ribs, skipping the outermost rib (towards the driversside). I put it back on normally, fired it up, and as soon as I go into boost hitting the throttle cable, the belt jumps over again.

I got a new belt thinking this one may be damaged from running like that for so long.

Nope, no damage. Popped the new belt on, tried it again and sure enough, if I pull hard enough on the throttle cable, the belt jumps again (towards the SC, not away).

I figured the reason the alternator belt kept flying off was because the SC belt being off a rib was causing the alternator pulley to spin awkwardly, throwing the belt.

What could be causing the SC belt to constantly jump a rib?

[newgsrdriver]

I should also add, the kit has been on for years. I did experience this a long time ago, and I replaced my aluminum idler pulleys with plastic pulleys and it hasn't happened since.

Also, I know the proper belt size is 4PK620, but no one ever has that in stock, so I run 4PK630. Do you think that could be the cause, running a slightly larger belt? Its either 610 or 630, and I seem to remember trying a 610 in the past without much luck in terms of shoehorning it on.

[JRCivic]

Nine times out of ten, the reason the blower belt runs inside toward the alternator one rib is because the alternator stabilizer bracket is installed INCORRECTLY.
Remember the proper washer/nut sequence for the upper tensioner is as follows:

FRONT STUD (closest to the block): Stud -> Nut.
REAR STUD (closest to the firewall): Stud -> Washer -> Washer -> Alternator stabilizer bracket -> Nut.

Usually, everyone puts one washer behind each nut and goes on about their business. This puts the alternator in a bind... and belts fly babee !!!

[JRCivic]

It could also be that you have somehow lost your lower alternator bolt... check there too.

[gsrteggie]

or it could be a larger belt. Order one from jackson if you cant get the right one at your parts store.

[jabroni95gsr]

it could be the belt, but the size that was supposed to fit on my car the 620 (i think?) was in no way in hell going to fit. I got a 625 at the local store and its worked perfectly for 5k miles...

[newgsrdriver]

Jim...

I think youre right. Surprise.

I looked today, and there is one washer behind each nut. It seems like it would be lopsided with both washers behind one nut?

Regardless, I guess Im going to have to do this. How much of a pain is it to remove this bracket and swap the washers? Can I just remove the SC belt tensioner pulley bracket and get it at that way, or am I going to have to remove the alternator?

[JRCivic]

It is not necessary to remove the alternator completely... you should be able to access the bolt/nut passing through the locator strap and the upper part of the alternator and then remove the strap... move the offending washer from the front stud to the rear one, replace the strap and re-tighten all three fasteners. It may be easier to access the upper alternator bolt/nut when the upper tensioner swing-arm (along with the upper tensioner pulley) is removed.

Good luck.