WTF !!! Question about crank pulley
Thread Starter
Racer
Joined: Mar 2006
Posts: 381
Likes: 3
WTF !!! Question about crank pulley
I've been having some pulley/belt noise that sounds like the bearings in one of the components is bad.
So I'm looking down at the serpentine belt, and the crank pulley is clearly not lined up with the other component pulleys. Whats more, the edge of the belt is actually riding off the edge of the crank pulley.
How can this be ? It's as if a washer or spacer is missing from end of the crank and allowing the pulley to ride inboard of the other component pulleys ?
So I'm looking down at the serpentine belt, and the crank pulley is clearly not lined up with the other component pulleys. Whats more, the edge of the belt is actually riding off the edge of the crank pulley.
How can this be ? It's as if a washer or spacer is missing from end of the crank and allowing the pulley to ride inboard of the other component pulleys ?
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
Common C5 failure.
Your crank pulley has 3 parts. The core, an elastomer band, and the outer shell which has the belt grooves.
Does your car have a chirping sound?
Your outer core is moving on the elastomer band seperating it from the core that is bolted to the crank.
You might as well buy an underdeive pulley to gain 9 rwhp, and since it's so much trouble (you have to pull the steering rack to get to the pulley) you might as well get a hotter camshaft.
Bad news, or good news.. You decide.
Your crank pulley has 3 parts. The core, an elastomer band, and the outer shell which has the belt grooves.
Does your car have a chirping sound?
Your outer core is moving on the elastomer band seperating it from the core that is bolted to the crank.
You might as well buy an underdeive pulley to gain 9 rwhp, and since it's so much trouble (you have to pull the steering rack to get to the pulley) you might as well get a hotter camshaft.
Bad news, or good news.. You decide.
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
The chirping is from the belt grooves not lining up anymore (compared to the belt)
With engine running, look/stare at the balancer, notice the groove have a slight wobble. The outer shell is clearance-fit over the elastomer... That's all holding it on. Over time the tolerances decide against your best wishes to seperate from the center.
ASP makes an okay underdrive pulley, Powerbond is a cheap (but good) choice too. All C5 pullies are the same, the problem was never addressed. n
With engine running, look/stare at the balancer, notice the groove have a slight wobble. The outer shell is clearance-fit over the elastomer... That's all holding it on. Over time the tolerances decide against your best wishes to seperate from the center.
ASP makes an okay underdrive pulley, Powerbond is a cheap (but good) choice too. All C5 pullies are the same, the problem was never addressed. n
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I used the POWERBOND and an ARP bolt. That sucker is never coming off. The powerbond pulley is a very good piece for the price!!!
iF YOU INSTALL an underdrive pulley of any brand, you will need a different size belt.
BC
iF YOU INSTALL an underdrive pulley of any brand, you will need a different size belt.
BC
Instructor
Joined: Jul 2006
Posts: 174
Likes: 4
From: West Palm Beach Fl
Hmmm, I'm having that same sound but mine goes away sometimes on it's own and sometimes it goes away with a little shot of silicon spray.
Comes back like to did recently after a nice wonderful rainfall like we've had the past ten days. Once I did notice it was noisy and the noise went away when I turned on the A/C. I didn't see anything unusual other than the belt didn't feel super tight. I figured it was just the belt needed replacing but now I'm gonna take a second look.
Comes back like to did recently after a nice wonderful rainfall like we've had the past ten days. Once I did notice it was noisy and the noise went away when I turned on the A/C. I didn't see anything unusual other than the belt didn't feel super tight. I figured it was just the belt needed replacing but now I'm gonna take a second look.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Drifting
Joined: Feb 2008
Posts: 1,765
Likes: 2
From: St. Clair Shores Mi
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
Hmmm, I'm having that same sound but mine goes away sometimes on it's own and sometimes it goes away with a little shot of silicon spray.
Comes back like to did recently after a nice wonderful rainfall like we've had the past ten days. Once I did notice it was noisy and the noise went away when I turned on the A/C. I didn't see anything unusual other than the belt didn't feel super tight. I figured it was just the belt needed replacing but now I'm gonna take a second look.
Comes back like to did recently after a nice wonderful rainfall like we've had the past ten days. Once I did notice it was noisy and the noise went away when I turned on the A/C. I didn't see anything unusual other than the belt didn't feel super tight. I figured it was just the belt needed replacing but now I'm gonna take a second look.
***
If the balancer doesn't have a wobble, then the next common failure is the belt tensioner (Top of engine by passenger cylinder head)
Seems likely since the load of turning on the a/c can change the tension on the belt.
Tensioners aren't expensive, very easy to unbolt and replace, or you could get a solid tensioner from Katech/etc.
Drifting
Joined: Feb 2008
Posts: 1,765
Likes: 2
From: St. Clair Shores Mi
well you are only a few bolts away to swap it out, so i would if you have the money to budget for cam/valve springs/pushrods/timing chain and maybe pump depending on mileage.
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
Ask yourself this question.... How long you really think you'll own that car?
If it's less than 3 years then you're wasting your money aside from repairs.
Instructor
Joined: Jul 2004
Posts: 177
Likes: 0
From: Tampa FL
No, because it usually doesn't happen until the car has quite a few miles on it. Mine went at about 100k miles. It's just one more part of the car that eventually wears out. It's not a design flaw.
Thread Starter
Racer
Joined: Mar 2006
Posts: 381
Likes: 3
Okay, but I've got to tell you, I'm 53 years old, and I have owned and driven many cars into the neighborhood of 200K or so, and I've yet to ever have an issue with a crank pulley wearing out.
Instructor
Joined: Jul 2006
Posts: 174
Likes: 4
From: West Palm Beach Fl
I answered your Pm, but I'll post here too incase this can help someone else.
***
If the balancer doesn't have a wobble, then the next common failure is the belt tensioner (Top of engine by passenger cylinder head)
Seems likely since the load of turning on the a/c can change the tension on the belt.
Tensioners aren't expensive, very easy to unbolt and replace, or you could get a solid tensioner from Katech/etc.
***
If the balancer doesn't have a wobble, then the next common failure is the belt tensioner (Top of engine by passenger cylinder head)
Seems likely since the load of turning on the a/c can change the tension on the belt.
Tensioners aren't expensive, very easy to unbolt and replace, or you could get a solid tensioner from Katech/etc.
