Sheared Supercharger Pulley

[FBO5.0]

Anybody ever seen this before? I've now had three pulleys do the same thing. The supercharger pulley keeps shearing off from where the faceplate of it bolts on to the hub. I'm not ready to blame the pulley, I'm more concerned that maybe the supercharger shaft is locking up. Turning the shaft by hand doesn't make any sound and it turns smoothly, and at idle I don't see any issues. Surely with how common these pulleys are, someone will have seen this before if it's because of the pulley. I now have the stock roush 85mm pulley made of a stronger metal out back on and I'm driving below 4000 rpm. Any info would be helpful

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[blackk3389]

I sheared my Whipple pulley off twice, but it was the bolts the sheared. not the pulley. turned out the bolts were not grade 8. theres a lot of torque on that thing when you hammer it. is there an after market pulley you can try, not familiar with VMP.

 

[FBO5.0]

I sheared my Whipple pulley off twice, but it was the bolts the sheared. not the pulley. turned out the bolts were not grade 8. theres a lot of torque on that thing when you hammer it. is there an after market pulley you can try, not familiar with VMP.

VMP is who made the aftermarket pulley for the Eaton (Roush) blower that I have. It's definitely made of a softer metal than the stock one, but if a pulley is turning freely, I don't see why this would happen.

 

[Proshop]

Please tell me you have contacted VMP about this??? They are good people and will definitely want to know about this.

 

[FBO5.0]

Please tell me you have contacted VMP about this??? They are good people and will definitely want to know about this.

When I bought the replacement pulley I emailed a picture of the failure. They just kinda sold me the new pulley. But I'm not on here trying to bash VMP at all. I'm not even blaming the pulley. I'm just seeing if anyone else has had this happen and was able to determine the cause.

 

[ZXMustang]

I would see if griptec makes a replacement. Trash that garbage VMP pulley.

 

[SheepDog]

VMP is who made the aftermarket pulley for the Eaton (Roush) blower that I have. It's definitely made of a softer metal than the stock one, but if a pulley is turning freely, I don't see why this would happen.

It really should'nt happen but the pulley isn't really spinning freely. It takes a lot of force to spin the blower, especially at high RPM with a small pulley. The force of compressing the air can take upwards of 100 horsepower or more, just to spin it. Call Griptec, I belive their pulleys are Made from billet 7075-T6

 

[Proshop]

When I bought the replacement pulley I emailed a picture of the failure. They just kinda sold me the new pulley. But I'm not on here trying to bash VMP at all. I'm not even blaming the pulley. I'm just seeing if anyone else has had this happen and was able to determine the cause.

Bash away please! If it were one defective pulley I’d say maybe just a bad production run or maybe just one out of who knows how many that failed. But three is just plain ridiculous as far as I’m concerned. Glad you contacted them but definitely not the response I would have expected from them…. As zxmustang said definitely time to upgrade to a better brand and I would keep on VMP about maybe some possible recoup of $.

 

[FBO5.0]

It really should'nt happen but the pulley isn't really spinning freely. It takes a lot of force to spin the blower, especially at high RPM with a small pulley. The force of compressing the air can take upwards of 100 horsepower or more, just to spin it. Call Griptec, I belive their pulleys are Made from billet 7075-T6

I'll look into that. My concern would be that if there is something wrong with the blower causing the shaft to lock up at certain moments, maybe I'd rather the pulley get shredded than have a more severe failure. Kinda like destroying a clutch instead of the transmission.

 

[SheepDog]

I'll look into that. My concern would be that if there is something wrong with the blower causing the shaft to lock up at certain moments, maybe I'd rather the pulley get shredded than have a more severe failure. Kinda like destroying a clutch instead of the transmission.

I would think that very loud, undesirable noises would be coming from it if it were intermittently locking up. I don't really think anything more severe would be happening. If the blower locks up, your belt will simply break or come off, or at least slip. I think if you can freely spin it by hand and you don't hear grinding, binding, angry noises from it, It is likely just that the pulley has too much stress and heat on it.

Any signs of belt slip? How does the blower oil look? ever changed it?

 

[Joshinator99]

I would see if griptec makes a replacement. Trash that garbage VMP pulley.

Another vote for ZPE Griptec. Drew over there is a solid guy and knows his stuff. I have had a Whipple on my Camaro for years now (both 2.9 and 3.0), have never had an issue with Griptec pulleys.

 

[Idaho2018GTPremium]

Looks like a bad pulley design to me. Those inverted ribs create weak points where they intersect with the bolt face plate. They are probably there to make the barrel stiffer, but they make the plate/barrel connection weaker.

The metal is also thin at the joint in general, but exceptionally thin at the inverted ribs where they meet the face plate. Not to mention, repeated thermal, tension, compression stresses every time the pulley goes around; and a stress crack at the rib/face plate interface would propagate immediately to the rest of the pulley, and fail.

 

[FBO5.0]

I would think that very loud, undesirable noises would be coming from it if it were intermittently locking up. I don't really think anything more severe would be happening. If the blower locks up, your belt will simply break or come off, or at least slip. I think if you can freely spin it by hand and you don't hear grinding, binding, angry noises from it, It is likely just that the pulley has too much stress and heat on it.

Any signs of belt slip? How does the blower oil look? ever changed it?

The belt did get some extremely minor damage from when the pulley failed. I've kept an eye on it and it doesn't seem to be progressing at all.
I have never changed the oil on the blower, but the blower hasn't been on the car for all that long. Definitely not enough miles to warrant changing it.

 

[HKusp]

How much tension do you have on that pulley? You may wanna try backing that down a bit. I can't believe you've had this happen three times and there's not something inherently wrong with your set-up. I doubt the shaft is locking up. Catastrophic things worse than the pulley breaking would happen if the shaft were locking up, in my opinion.

 

[Cory S]

Justin said he had an entire lot (upwards of 500 pullies) of these come in with a defect in manufacturing (stressed metal around the front radius) It’s not your compressor. Buy a ZPE Griptec and enjoy.

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