Pulley Wobble
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Pulley Wobble
My AIR pump pulley (with spacer) has a minor vertical wobble to it. The three mounting bolts are snug and the spacer looks fine/true. I find these things are fairly pricey. Can the pulley be made true again?
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Pulley Wobble (paul79)
I make pulleys and I don't see how you could remachine a steel pulley to make it true especially a vertical wobble. I also wonder how it could have got eccentric in the first place.
Norval
Norval
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Re: Pulley Wobble (norvalwilhelm)
Good question, Norval! I do not have the answer. Perhaps it has always been that way. I just noticed it when I replaced an AIR pump a few weeks ago. I also noticed the belt seems too "fat" for the groove: it rides on the edges and does not seat. I will get a photo up on that later. There must be a "thinner" belt available.
Le Mans Master
Joined: Apr 2000
Posts: 7,562
Likes: 9
From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Re: Pulley Wobble (paul79)
It is possible to amke the pulley run true again if it's because of the bore to the groove not being concentric. If you have access to a machine shop, they should be able to turn the bore out to a larger size if there is enough material to do so.
It doesn't matter what size you turn the bore to, as long as you'll be able to fit a bushings into it afterwards. The idea is to get it big enough so that when you press the bushing into the bore, that you can finish the bushings ID size to the size that is needed. If your chucking on the OD when finishing your new bore, you should establish a new & improved R/O if the OD is indicated in before finishing the bore.
I had a similar problem last year where my powersteering pump pulley was wobbling horribly. The bore was basically destroyed, & the pulley was originally driven with a key on the pump. Somehow the pulley slipped and the key wrecked the pulley bore. I turned the bore bigger, made a bushing and pressed it into the pulley. Being that the pulley was no longer going to be driven by a key, I made the final bore .001 smaller than the pump shaft causing an interferance fit. I heated the pulley bore with a small propane torch to expand the the material, the pulley slipped right onto the shaft and has workede great since.
My only other option was to but a new pump and pulley (ouch !) .
You state there are 3 mounting holes, so look to see if it's not them causing the runout your describing 1st. Good luck.
It doesn't matter what size you turn the bore to, as long as you'll be able to fit a bushings into it afterwards. The idea is to get it big enough so that when you press the bushing into the bore, that you can finish the bushings ID size to the size that is needed. If your chucking on the OD when finishing your new bore, you should establish a new & improved R/O if the OD is indicated in before finishing the bore.
I had a similar problem last year where my powersteering pump pulley was wobbling horribly. The bore was basically destroyed, & the pulley was originally driven with a key on the pump. Somehow the pulley slipped and the key wrecked the pulley bore. I turned the bore bigger, made a bushing and pressed it into the pulley. Being that the pulley was no longer going to be driven by a key, I made the final bore .001 smaller than the pump shaft causing an interferance fit. I heated the pulley bore with a small propane torch to expand the the material, the pulley slipped right onto the shaft and has workede great since.
My only other option was to but a new pump and pulley (ouch !) .You state there are 3 mounting holes, so look to see if it's not them causing the runout your describing 1st. Good luck.
