tion

I bought chrome pulleys to put on my 79 L48. When I went to loosen the bolts holding the crank pulleys the entire balancer turned. I noticed the center bolt holding the balancer was loose. I tightened that and let the rust buster do its thing on the pulley bolts. It seems that the balancer moved a little then also. Did my balancer "slip"? What does that mean? Or was I turning the crank and pistons? The engine had sat for a few weeks but I'd think that the engine would have more compression than that. I also thought that the balancer shaft had keyways on it.
Newbee thanks!

66roadster427

the key is only for aligning the balancer when you install it - it is not designed to keep it from slipping. I would replace the broken (or missing) key, get a balancer installer (you can rent them from Autozone) and re-install the balancer all the way in and hope that the only reason it was loose is because it started to come off the crank snout. As it starts to go back on the crank it should get tighter and tighter to install. If it doesnt tighten back up then it has worn the crank snout down and wrecked the crank. Before you reinstall the balancer you will need to replace the seal in the timing cover because it has probably been chewed up by the balancer coming loose.

Fingers crossed!

Aggitated Monkey

You need to make sure that balancer is all the way on and tight. If it was not loose then you may have been turning the crank some. The crank will spin fairly free until you come aginst compression. It doesn't shoud like you turned it that far.

w1ctc

You can easily turn the crank with a socket wrench on the balancer nut. A 100 ft lbs is easy to generate with hand tools.

stingr69

No it did not slip. There is a 1/4" ring of rubber wrapped around the center hub of the damper. On the outermost part of the damper assy is a thick solid iron ring that is attached to the rubber ring. The damper can slip if the outer thick iron ring and the rubber come apart from the center hub. The damper is keyed to the crank at the center hub portion of the damper assy.

All of the bolts you were trying to remove are threadded into the center hub that is keyed to the crank so if anything moved when you applied force to the bolts, the whole engine - crank, rods, pistons, damper, etc was rotating along with it.

-Mark.

75 Hot One

You should remove the balancer & confirm that the key is in place. If the key is in place & is the proper size (ensure it is tight in the keyway), it will prevent the balancer from rotating on the crankshaft. On the other hand, if the proper key is in place, you can conclude that the rotation you noticed was movement of the crankshaft. The center bolt in the balancer is there to keep the balancer engaged on the key by ensuring the balancer doesn't move forward & disengage.

wombvette

Sounds like you just turned the engine to me. I would just confirm that the mark it still at TDC with #1. These years have a problem with balancer slip, but that is the outer ring, and not the shaft. You would not have been pulling on the outer ring.

7T1vette

Put some significant torque on the outer portion of the balancer to be sure that the elastomer has not "failed" [you didn't indicate that the balancer was new, so I'm assuming it is old and could be defective]. If the balancer is a new part, follow the advice above...if not, test it for possible re-use OR just replace the thing.

tion

Thanks all, I'll check TDC first before I pull the balancer. Car was running fine before I brought it in for the winter to add some chrome.