also install a under drive pulley while you have it off..
Help, crank pulley loose!
Thread Starter
Racer
Joined: Jun 2004
Posts: 274
Likes: 0
From: Pickens SC
Help, crank pulley loose!
The bolt that holds the crank pulley came loose. Pulley wobbling very badly. How much damage could I have done? What do I need to do to fix this? I expect to have to drop the steering rack. Any info, even if I don't want to hear it, will be helpful. Thanks Mike
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Former Vendor
Joined: Apr 2007
Posts: 1,331
Likes: 4
From: Jacksonville Florida
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Should the damper bolt torque be checked periodically? I've never heard of anyone having a problem with the damper bolt coming loose from the factory if it wasn't messed with.
Le Mans Master
Joined: Feb 2006
Posts: 5,267
Likes: 40
From: Phoenix AZ
My friend bought a 99 from a guy who drove it real mellow. After 2 weeks of raping on it, we were driving and shredded half of the belt. Sure enough, the pulley walked and the bolt was loose.
He had GMPP and took it in. Those freakin butt burglar stealership guys said they had to put a new crank in it. I took a look at the car while it was on the rack with the pulley off and inspected it. Both the crank and pulley were fine, it just needed a new bolt. They insisted on saying they needed a crank and charged GM the warranty work. I know for a fact they didnt replace anything other than the Pulley and bolt.........I checked the car after supposed crank replacement.
Midway Chevrolet
Being a former dealership tech myself, I was a little pissed off, but it wasnt my car.
He had GMPP and took it in. Those freakin butt burglar stealership guys said they had to put a new crank in it. I took a look at the car while it was on the rack with the pulley off and inspected it. Both the crank and pulley were fine, it just needed a new bolt. They insisted on saying they needed a crank and charged GM the warranty work. I know for a fact they didnt replace anything other than the Pulley and bolt.........I checked the car after supposed crank replacement.
Midway Chevrolet
Being a former dealership tech myself, I was a little pissed off, but it wasnt my car.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
If the original bolt backed out, it may very well be the harmonic damper is starting to go and needs replacement. I would get a new damper, seal and bolt. Personally, I would also pin the crank and get a damper with a key to engage the pin.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Nov 2005
Posts: 5,451
Likes: 2
From: East Peoria Illinois
My friend bought a 99 from a guy who drove it real mellow. After 2 weeks of raping on it, we were driving and shredded half of the belt. Sure enough, the pulley walked and the bolt was loose.
He had GMPP and took it in. Those freakin butt burglar stealership guys said they had to put a new crank in it. I took a look at the car while it was on the rack with the pulley off and inspected it. Both the crank and pulley were fine, it just needed a new bolt. They insisted on saying they needed a crank and charged GM the warranty work. I know for a fact they didnt replace anything other than the Pulley and bolt.........I checked the car after supposed crank replacement.
Midway Chevrolet
Being a former dealership tech myself, I was a little pissed off, but it wasnt my car.
He had GMPP and took it in. Those freakin butt burglar stealership guys said they had to put a new crank in it. I took a look at the car while it was on the rack with the pulley off and inspected it. Both the crank and pulley were fine, it just needed a new bolt. They insisted on saying they needed a crank and charged GM the warranty work. I know for a fact they didnt replace anything other than the Pulley and bolt.........I checked the car after supposed crank replacement.
Midway Chevrolet
Being a former dealership tech myself, I was a little pissed off, but it wasnt my car.
Le Mans Master
Joined: Nov 2005
Posts: 5,451
Likes: 2
From: East Peoria Illinois
I know alot of the guys say get aftermarket this, aftermarket that...but this is one piece that if you are going to replace, get a better one. the stock one is garbage and wobbles. If and when I take mine apart again, I will switch to a aftermarket better quality piece. But def get a new bolt, you HAVE to. Also, vettenuts really knows his stuff with this pulley, talk to him about what tool to use to put the pulley back on
Safety Car
Joined: Dec 2004
Posts: 3,526
Likes: 20
From: Santa Fe TX
This is probably a moot point - but are you sure the bolt is loose?
The Crank Pulley can wobble without the bolt being loose since it has a rubber dampener that can start to seperate.
If its just barely wobbling, it may not be as big of a deal as you think, but probably still needs to be changed.
The Crank Pulley can wobble without the bolt being loose since it has a rubber dampener that can start to seperate.
If its just barely wobbling, it may not be as big of a deal as you think, but probably still needs to be changed.
Thread Starter
Racer
Joined: Jun 2004
Posts: 274
Likes: 0
From: Pickens SC
No question about it.
It is completely loose. The only reason that all of it is not laying on the "tail of the dragon" is because there was not enough room for it to fall out. The "dragon" is a local stretch of road with alot of curves. I am trying to decide on which parts to put back on. I am willing to spend the extra money to make it right, so that I don't have to do this again. I think whoever tightened the bolt last time did not change the bolt. The car is low milage with heads, cam, underdrive pulley etc. Anyway, if you have any suggestions as to which company makes the best stuff, let me know. Thanks Mike 
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Seal: Get the GM part
Balancer: I am running the ATI which is a good unit, but it is also more than others. It comes with a keyway for pinning the crank and is fully rebuildable. It is 10% underdrive
Bolt: You can go stock or ARP, I pinned the crank and used the ARP bolt installed per the ARP instructions which differ from the stock bolt.
Get/make an installation tool. Don't try to use a longer bolt, a lot of guys have damaged their crank threads using this method. In my opinion it is very high risk. This is the tools I made for under $20 to re-install the pulley (harmonic damper).
Balancer: I am running the ATI which is a good unit, but it is also more than others. It comes with a keyway for pinning the crank and is fully rebuildable. It is 10% underdrive
Bolt: You can go stock or ARP, I pinned the crank and used the ARP bolt installed per the ARP instructions which differ from the stock bolt.
Get/make an installation tool. Don't try to use a longer bolt, a lot of guys have damaged their crank threads using this method. In my opinion it is very high risk. This is the tools I made for under $20 to re-install the pulley (harmonic damper).
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
It's still hard for me to believe some guys have had the factory installed bolt back out or come out. The only thing I could imagine is if that the factory bolt wasn't torque it right by GM.
