Pulley Failure - ZR-1 Net Registry Forums

Locobob · 05-23-2019

So a couple of years ago my tensioner went bad and I rebuilt it using a combination of stuff including some L98 parts and this aluminum pulley from UPR products (the pulley specs as a 85-93 Mustang ultra light tension/idler pulley). I remember I followed the tensioner rebuild project of someone on here, so if you have this pulley I suggest you check it. I can't think of any reason other than poor build quality as the cause, there are actually several holes although you can only see the one in the pic. The belt shows some damage too, I was noticing some odd coolant temp and voltage fluctuations which is why I started poking around. Guess I'll go back to the factory pulley.

Ccmano · 05-23-2019

Bearing failure?
H

Locobob · 05-23-2019

Quote:

Originally Posted by Ccmano

Bearing failure?
H

Possibly... I have been noticing a silvery oily residue under the air horn and around the general vicinity of the belt. Although I think that is from a leak in the A/C system which is another area I need to address and that could also account for belt slippage.

XfireZ51 · 05-23-2019

LB,

Looks like it wasn’t worth the extra hp.

Ccmano · 05-23-2019

Judging from the hole in the pulley (which is aluminum) looks like it froze and the belt wore a hole in it, might be the source of your silvery residue?
H

Locobob · 05-23-2019

Quote:

Originally Posted by Ccmano

Judging from the hole in the pulley (which is aluminum) looks like it froze and the belt wore a hole in it, might be the source of your silvery residue?
H

Hmmm, that's a good possibility

Paul Workman · 05-23-2019

Quote:

Originally Posted by Ccmano

Judging from the hole in the pulley (which is aluminum) looks like it froze and the belt wore a hole in it, might be the source of your silvery residue?
H

Yup. Beat me toit!! Pully seizing up.

Bob: I replaced mine with a GM pulley for a C4 LT1. Works no for over 10 years! Also, Jerry's Gaskets has ZR-1 pulleys, IIRC.

Jagdpanzer · 05-23-2019

After looking closely at the photo appears it could have started as fatigue crack.
Is the center section of the pulley solid or spoked?

Sent from my iPhone using ZR-1 Net Registry

efnfast · 05-23-2019

Pretty sure Jim Voter had that exact same pulley fail on the way home from BG

HAWAIIZR-1 · 05-23-2019

It’s hard to imagine that billet aluminum is weaker than plastic (stock) and I agree it has to be bearing failure with a seize that heated and burned by the belt friction. It would seem that would be noticeable though. I’m tempted to go back to stock myself. I guess another reminder to make America great again and we need better quality parts overall and stop outsourcing if this is from China.

I can’t remember the Dynomite post. Was it bigger and needed and larger belt too? If same sized belt used it could cause more tension on the pulley than it should have? Thanks for sharing since some of us did this mod.

Sent from my iPhone using ZR-1 Net Registry

05-23-2019	#1
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Pulley Failure So a couple of years ago my tensioner went bad and I rebuilt it using a combination of stuff including some L98 parts and this aluminum pulley from UPR products (the pulley specs as a 85-93 Mustang ultra light tension/idler pulley). I remember I followed the tensioner rebuild project of someone on here, so if you have this pulley I suggest you check it. I can't think of any reason other than poor build quality as the cause, there are actually several holes although you can only see the one in the pic. The belt shows some damage too, I was noticing some odd coolant temp and voltage fluctuations which is why I started poking around. Guess I'll go back to the factory pulley. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

05-23-2019	#2
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Pulley Failure Bearing failure? H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

05-23-2019	#4
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: Pulley Failure LB, Looks like it wasn’t worth the extra hp. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

05-23-2019	#5
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Pulley Failure Judging from the hole in the pulley (which is aluminum) looks like it froze and the belt wore a hole in it, might be the source of your silvery residue? H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

05-23-2019	#8
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,661	Re: Pulley Failure After looking closely at the photo appears it could have started as fatigue crack. Is the center section of the pulley solid or spoked? Sent from my iPhone using ZR-1 Net Registry __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

05-23-2019	#9
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,484	Re: Pulley Failure Pretty sure Jim Voter had that exact same pulley fail on the way home from BG

05-23-2019	#10
HAWAIIZR-1 Join Date: May 2010 Location: Japan Posts: 3,582	Pulley Failure It’s hard to imagine that billet aluminum is weaker than plastic (stock) and I agree it has to be bearing failure with a seize that heated and burned by the belt friction. It would seem that would be noticeable though. I’m tempted to go back to stock myself. I guess another reminder to make America great again and we need better quality parts overall and stop outsourcing if this is from China. I can’t remember the Dynomite post. Was it bigger and needed and larger belt too? If same sized belt used it could cause more tension on the pulley than it should have? Thanks for sharing since some of us did this mod. Sent from my iPhone using ZR-1 Net Registry __________________ Craig "ZR-1 NO KA 'OI" "ZR-1 ICHIBAN" 1995 #228 Black/Black with Dunn Heads ZR-1 owner since September 2003 ZR-1 Net Registry Founding Member #0074 NCM Lifetime Member #2048 Last edited by HAWAIIZR-1; 05-24-2019 at 06:11 PM.