crankpulley moves

[90hurst/oldsguy]

does anyone knows what will cause the crank pully to move fowards and backwards. the bolt is still there and appears to be tight.
If the bolt is the culprit of being loose what size is it on a olds 350.the center bolt to specific

 

[1evilregal]

it just the pulley, or the entire harmonic balancer moving back and forth as well? my first thought was that the thrust bearing on the main bearing cap is shot... are you hearing alot of hammering noise?

 

[Fox80]

Look under the car while someone revs it slightly if you see the balancer moving in and out if the front seal then the thrust bearing is shot, as the cam walks back and forth it pulls the crank as well. You didn't put your balancer on with a hammer at some point did you? A car with a manual trans is hard on the thrust bearing as well, if you find it's bad you could drop the pan and trans and do the mains, but way better off to pull it and ring and bearing it

 

[olds307 and 403]

The center bolt is 1 1/8.

 

[Blake442]

Is just the pulley moving, or is the balancer moving too?
The large bolt in the center only holds the balancer to the crank.
The pulley is held by the four smaller bolts...

 

[90hurst/oldsguy]

Yes the pulley and the balancer moves but no hammering noises at all. i do recall switching the pulley about a year ago. Yes when you rev the car the balancer and pulley moves foward. sorry for repeating myself. if the belts are off you can move the whole thing. i think the balancer did get hit with a hammer.

 

[RegalBegal]

Sounds like the thrust bearing.

 

[90hurst/oldsguy]

o boy.there isnt any weird noises,but it uses some oil when you drive for a few days been trying to solve that problem. if that is the cast time to go to a 455 and be done and find another body for the 350 when its fixed right. hopefully thats not the problem

 

[Fox80]

Not sure why it would make noise, the thrust plate would have to be completely gone for the crank to touch the main cap. You probably wouldn't be able to keep belts on it at that point. If the balancer was driven on with a hammer, more than likely that's what caused it. If your on a budget you could pull the motor and change just the thrust bearing main, if you open it and the crank has touched the main cap the crank is junk, I have had cars that needed this done, did it motor in the car once, on SBC with two piece rear main, didn't pull the trans just slid the converter back, took the crank and ring gear out together. Not bad job, just sucks doing it on your back

 

[-83MONTESS-]

You sure the balancer isnt just bent and/or the crank snout? If someone took a hammer to it anything could be bent which when rotating would look like it was moving. Just an idea :? If you have a dial indicator you could find out if the thrust bearing is gone by measuring end play. That would probably be the easiest way.