mlm

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

mvvette97

yep, drop the rack and get a new balancer. Oh, get a new bolt for sure

ZeeOSix

Was the crank pulley/damper ever worked on? Don't think it's common for that bolt to loosen by itself since its torque is almost 250 ft-lbs.

0euro@EFIAlchemy.com

Actually its a pretty common problem for our cars, get a new pulley and i highly suggest you get the ARP pulley bolt, that sucker will never back off again

SLPRC5

also install a under drive pulley while you have it off..

ZeeOSix

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.

gpracer1

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.

vettenuts

Actually, there is no torque value on this bolt, only a rotation. You can mark it and keep an eye on the marks. If you use a torque wrench to install, it isn't correctly preloaded and it can back out as a result.

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.

02gt350

wow, sounds like a local dealer here called Green chevrolet....very unprofessional

02gt350

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

jedblanks

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.

mlm

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

mlm

Anybody have good results with certain seals, bolts or balancer?

vettenuts

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).

mlm

Thanks, I may have a few more questions once I get it taken apart.

ZeeOSix

So someone was messing around with the crank pulley.

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.