balancer bolt keeps backing out
balancer bolt keeps backing out Ok this is twice now that the bolt has backed out which is why I am posting. Both times I seated it per GM instructions and used a new bolt. The engine is high mileage and heads/cam. If I am going in a third time just for this, I want to know why it's doing it and how to prevent it. I have my thoughts but I'm curious to hear what others have to say. The current balancer is factory and does wobble a little bit but nothing I haven't seen on stock cars before. I'm planning to put a new under drive balancer on while I am in there but I'm not looking to that as a cure for the bolt not staying torqued.
Thoughts/suggestions?
Thanks
Thoughts/suggestions?
Thanks
Go ARP next time.....torque to 250 ft/bs with red loctite and forget about it.
The OEM bolts are crap (rubber bands) in comparison
Its not cheap at $25 but you get what you pay for once again and what is your time worth screwing around with a new factory fastener (again).
-Tony
The OEM bolts are crap (rubber bands) in comparison
Its not cheap at $25 but you get what you pay for once again and what is your time worth screwing around with a new factory fastener (again).
-Tony
Explain in detail how you installed the bolt.
Ok this is twice now that the bolt has backed out which is why I am posting. Both times I seated it per GM instructions and used a new bolt. The engine is high mileage and heads/cam. If I am going in a third time just for this, I want to know why it's doing it and how to prevent it. I have my thoughts but I'm curious to hear what others have to say. The current balancer is factory and does wobble a little bit but nothing I haven't seen on stock cars before. I'm planning to put a new under drive balancer on while I am in there but I'm not looking to that as a cure for the bolt not staying torqued.
Thoughts/suggestions?
Thanks
Thoughts/suggestions?
Thanks
My thoughts:
#1- While I do agree with Tony that the stock bolts are crap, they should not be backing out. If it is, there's a reason for it. Usually, a defective harmonic balancer.
#2- Now would be a good time to go ahead and order an SFI approved underdrive of your choice. I like the ASP's because they're lighter than the Powerbond, but the Powerbond is cheaper and easier to get. Last I check, ASP was on back order (again).
#3- The GM reinstall procedure is crap. Once the pulley is seated w/ 250ft lbs, take your new GM bolt and coat the threads with red loctite PASTE. Then TQ to 150 ft lbs. Done. I've used this method for years on 100's of pulleys. Never had a problem.
#1- While I do agree with Tony that the stock bolts are crap, they should not be backing out. If it is, there's a reason for it. Usually, a defective harmonic balancer.
#2- Now would be a good time to go ahead and order an SFI approved underdrive of your choice. I like the ASP's because they're lighter than the Powerbond, but the Powerbond is cheaper and easier to get. Last I check, ASP was on back order (again).
#3- The GM reinstall procedure is crap. Once the pulley is seated w/ 250ft lbs, take your new GM bolt and coat the threads with red loctite PASTE. Then TQ to 150 ft lbs. Done. I've used this method for years on 100's of pulleys. Never had a problem.
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Also, read your signature and then did a google search, laughed for quite a bit at some of the bumper stickers.
To the OP, was the same damper re-installed? I have found that once they spin on the crank snout they lose some of their interference fit and will keep spinning the bolt out. I would change the harmonic damper (pulley) to a new one of your choice. Personally, I prefer the ATI damper.
Last edited by vettenuts; Apr 5, 2010 at 05:31 PM.
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One other thing to consider:
Shoot a bunch of brake cleaner in the crank threads to make sure there's not any garbage in there...then blow it all out with compressed air (with a rag wrapped around the end of the crank snout to lessen the "cloud" of brake cleaner that will shoot back out at you)...make sure it's all dry, then red loctite...and torque to spec.
Shoot a bunch of brake cleaner in the crank threads to make sure there's not any garbage in there...then blow it all out with compressed air (with a rag wrapped around the end of the crank snout to lessen the "cloud" of brake cleaner that will shoot back out at you)...make sure it's all dry, then red loctite...and torque to spec.
The way I install them, heat the hub of the balancer with a propane torch, evenly for about 10 minutes ( or put it in the oven for 20 minutes@ 220º), the balancer should slide on the crankshaft with some resistance, make sure balancer is fully seated. Take new bolt, put red loctite on the threads, tighten to 37ft/lbs, make an index mark on the balancer bolt, move it past 90º roughly 100º is about the most you will get out of it.
