Some information on my setup and the history of it. 1998 6 speed with the novi 1500 6 rib. In the last 3 weeks I have broken the waterpump pulley. The first one was the original with 2500 miles on it since supercharging. The second water pump pulley I may have played a part in the belt not being tight enough and sheared that pulley off. Long story short I ended up buying a prw performance waterpump with a bolt on billet steel pulley in hopes that it would remedy my issue. Just to be safe when the new pump came in I used a micrometer and check everything compared to stock waterpump to make sure there was no casting difference or mounting boss difference and all check out exact before i installed the new performance pump. My concern is that the belt is almost a full rib off on the waterpump pulley. Upon further investigation I fount both Delco pump pulleys to have the same wear on them as the new one indicating it may have been like that since last year. I checked my balancer and have zero wobble. I also checked every pulley and replaced the supercharger tensioner pulley due to bearing play. I also noticed hammer marks on the back side of the supercharger pulley on a brand new kit I purchased not even a year ago. What the hell is going on with this. <br > I don't know what else to do. The belt appears to be straight with zero defects in the alignment. I need some help on this one because now I don't even want to drive the car for fear of the belt breaking and leaving me stranded. Any help. Doug ? Chris? Anyone. I almost feel like the spacer behind the supercharger pulley could be machined down a little and fix this ? I don't know. <br > <br >

 

After further inspection it looks to be off center on the supercharger side. If I look directly down from the supercharger pulley to to idler/ tensioner pulley directly below ( the one you adjust belt tension with on the supercharger bracket it appears to be slightly off leading me to believe the supercharger pulley has to come forward towards the radiator. It looks as the though the spacer behind the supercharger pulley is too thick. Anyone else ever have this issue. I must have never noticed it since day one.

 

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99% of the time; a Laser Alignmenf tool such as the one from gates is the only way to tell if your belt / pulley Alignment is off.


Are you throwing belts?

 

No. Not throwing any belts

 

laser tool is the only way. even being off a few thousandths can cause issues and you'll never see that by eye.

 

It's off by one rib which is 134 thousandths. Gonna have to machine the pulley spacer by 100 thousandths and try again. Ugh

 

Before you do that there are other things to check. It is rarely the SC pulley that is off, those are fixed values with little to no deflection. Looking at the picture you posted where you can see the rib off center, it is most likely just an adjustment of the tensioner bracket lower spacer.
It looks like the belt is towards the engine correct? If so shorten the lower spacer on the tensioner assembly, that will kick the top of the tensioner out, thus bringing the belt back in line.

This happens from differences in AC bracket castings or if it has been removed etc.

 

The lower spacer is threaded with a jam nut, so it is very easy to make this adjustment.

Hope that helps, feel free to call us if you would like to discuss this in length.

 

I'll call the shop and ask for you around 4 today Doug. I'm a little confused

 

Doug this is the tensioner setup on my 1998 <br >

 

My belt gets pulled 1 rib towards the engine after mexico trips.

Explain like I am 5, loosen that nut? Not sure how I shorten the lower spacer to be honest.

 

The bracket below that. Not what you have circled

 

It's the bracket that that is bolted to... not that

 

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"cone moves out" does that mean the cone moves towards the motor? Tighten the cone and it moves towards the tensioner.

 

Yes

 

As you tighten the "cone it tips the top of the tensioner out. If you turn the cone counter clockwise it tips the tensioner In toward the engine