Help!! Crank is loose again
Thread Starter
Pro
Joined: Oct 2004
Posts: 591
Likes: 0
From: Las Vegas NV
Help!! Crank is loose again
So I had a issue with my crank bolt coming loose. Don't know why. Replaced the bolt again, took it to 240 lbs and now it has come loose again. Any ideas what this could be from? Thanks for any help. Car is an 03 Z06 with heads/cam full bolt ons and 150 shot.
Pro
Joined: Jan 2006
Posts: 643
Likes: 2
From: Alexandria Northern Virginia
I am not sure where the 240 ft lbs comes from. That is the torque to mount the balancer but the GM book is VERY specific about first and second passes being done on the bolt.
New bolt, red loctite. First pass is something like 38 ft lbs. NEXT AND MOST IMPORTANT is the torque 140 DEGREES of rotation. If you dont have a degree index, get one. cheap and easy to use.
http://www.matcotools.com/ProductImages/tag281.jpg
Theres a picture of one. 140 degrees takes EVERYTHING I have to get it that tight (6' 190lbs and in shape) on a 26 inch breaker bar. Longer pipe would make it easier, but I couldn't get the space under the car. My torque wrench is a 250 pounder and it pops LOOONG before I reach 140 degrees.
Sorry you have to do the job again man, just sounds like the bolt is not tight enough. Unless the threads are galled up, which you would know as you pull the bolt back out, you are good to go.
Cassidy
New bolt, red loctite. First pass is something like 38 ft lbs. NEXT AND MOST IMPORTANT is the torque 140 DEGREES of rotation. If you dont have a degree index, get one. cheap and easy to use.
http://www.matcotools.com/ProductImages/tag281.jpg
Theres a picture of one. 140 degrees takes EVERYTHING I have to get it that tight (6' 190lbs and in shape) on a 26 inch breaker bar. Longer pipe would make it easier, but I couldn't get the space under the car. My torque wrench is a 250 pounder and it pops LOOONG before I reach 140 degrees.
Sorry you have to do the job again man, just sounds like the bolt is not tight enough. Unless the threads are galled up, which you would know as you pull the bolt back out, you are good to go.
Cassidy
Safety Car
Joined: Jun 2005
Posts: 4,977
Likes: 256
From: St. Louis Missouri
Crankshaft is out of balance and the pulley is walking off. You probably thrashed your main bearings and sent metal throughout the engine. Rebuild time.
Just kidding.
I've never had this problem. Perhaps an ARP bolt would be worth a try.
Just kidding.
I've never had this problem. Perhaps an ARP bolt would be worth a try.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
If you re-used your stock pulley I have always felt that it loses some of its interference fit and it more likely to spin than a new one. Correct procedure should be followed too, but I have always had a suspicion that re-use contributes to this happening.
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
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Burning Brakes
Joined: Aug 2000
Posts: 889
Likes: 0
From: DFW tx
Take it to a shop that knows what they are doing.
I did my own h/c job back in '02. Pulley got lose after 50 miles. Took it to a local shop that specializes in vettes, no problems since. Worth the $$ for the fact that they know how to it, and did it right.
I did my own h/c job back in '02. Pulley got lose after 50 miles. Took it to a local shop that specializes in vettes, no problems since. Worth the $$ for the fact that they know how to it, and did it right.
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
) and pin the crank. The pulley is spinnig on the crank and backing out the bolt.
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
Heres what you need to do to resolve your issue.
Remove all the old crap and trash the old stuff. Purchase a new Powerbond damper. The power bond damper has a key way that will allow you to side pin the crank. Beg, borrow or purchase a side crank pinning kit and pin the crank. That process sounds very complicated but,,,,it is amazingly simple and takes about 30 minutes TOPS to preform.
The crank snout is most likely worn from the old dampers spinning on the crank shaft (which is normally machined to a TIGHT press fit with the stock damper. ) and will not support installing a stock or an aftermarket damper without pinning. The pin prevents the damper from slipping or spinning on the crank. That movement causes the bolt to come loose.
Pin the crank and install a new Powerbond damper.
Bill Curlee
Remove all the old crap and trash the old stuff. Purchase a new Powerbond damper. The power bond damper has a key way that will allow you to side pin the crank. Beg, borrow or purchase a side crank pinning kit and pin the crank. That process sounds very complicated but,,,,it is amazingly simple and takes about 30 minutes TOPS to preform.
The crank snout is most likely worn from the old dampers spinning on the crank shaft (which is normally machined to a TIGHT press fit with the stock damper. ) and will not support installing a stock or an aftermarket damper without pinning. The pin prevents the damper from slipping or spinning on the crank. That movement causes the bolt to come loose.
Pin the crank and install a new Powerbond damper.
Bill Curlee
Burning Brakes
Joined: Jul 2007
Posts: 799
Likes: 16
From: Kansas City area
Replaced my stock crank pulley with Powerbond (as suggested above). We used an ARP bolt (that's where the 240 ft lbs spec comes from). No problems since. No pinning. 125 shot on my stock bottom end.
Melting Slicks
Joined: Sep 2003
Posts: 2,062
Likes: 117
Hi Bill,
Is the Powerbond 25% UD Corvette Balancer Pulley #25-PBU1117SS25 @ $199.99 the crank pinned one you are talking about?
REF: http://www.texas-speed.com/shop/item...d=629&catid=16
Thanks in advance
Christian
PS: I just spinned my second ASP on my new 416...
Is the Powerbond 25% UD Corvette Balancer Pulley #25-PBU1117SS25 @ $199.99 the crank pinned one you are talking about?
REF: http://www.texas-speed.com/shop/item...d=629&catid=16
Thanks in advance
Christian
PS: I just spinned my second ASP on my new 416...
Heres what you need to do to resolve your issue.
Remove all the old crap and trash the old stuff. Purchase a new Powerbond damper. The power bond damper has a key way that will allow you to side pin the crank. Beg, borrow or purchase a side crank pinning kit and pin the crank. That process sounds very complicated but,,,,it is amazingly simple and takes about 30 minutes TOPS to preform.
The crank snout is most likely worn from the old dampers spinning on the crank shaft (which is normally machined to a TIGHT press fit with the stock damper. ) and will not support installing a stock or an aftermarket damper without pinning. The pin prevents the damper from slipping or spinning on the crank. That movement causes the bolt to come loose.
Pin the crank and install a new Powerbond damper.
Bill Curlee
Remove all the old crap and trash the old stuff. Purchase a new Powerbond damper. The power bond damper has a key way that will allow you to side pin the crank. Beg, borrow or purchase a side crank pinning kit and pin the crank. That process sounds very complicated but,,,,it is amazingly simple and takes about 30 minutes TOPS to preform.
The crank snout is most likely worn from the old dampers spinning on the crank shaft (which is normally machined to a TIGHT press fit with the stock damper. ) and will not support installing a stock or an aftermarket damper without pinning. The pin prevents the damper from slipping or spinning on the crank. That movement causes the bolt to come loose.
Pin the crank and install a new Powerbond damper.
Bill Curlee
Le Mans Master
Joined: Oct 2003
Posts: 6,126
Likes: 19
From: Streamwood illinois
You can pin any crank and balancer. Even a stock balancer can be pinned. Just use an A&A crank pinning tool. I can lend you one for the cost of shipping if you'd like. It even has a pin in there, all you need is a drill bit (that may even be in there)
Dave
Dave
Le Mans Master
Joined: Jan 2009
Posts: 6,226
Likes: 33
From: Morton illinois
St. Jude Donor '14-'15
red lock tight dosnt mean poop if you are TQing this bolt that much. I switched to the ARP bolt when I built my 416. if it keeps coming loose, something is not jiving.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Hi Bill,
Is the Powerbond 25% UD Corvette Balancer Pulley #25-PBU1117SS25 @ $199.99 the crank pinned one you are talking about?
REF: http://www.texas-speed.com/shop/item...d=629&catid=16
Thanks in advance
Christian
PS: I just spinned my second ASP on my new 416...
Is the Powerbond 25% UD Corvette Balancer Pulley #25-PBU1117SS25 @ $199.99 the crank pinned one you are talking about?
REF: http://www.texas-speed.com/shop/item...d=629&catid=16
Thanks in advance
Christian
PS: I just spinned my second ASP on my new 416...