Posi-Traction Clutch Pack replacement cost estimate

[Gerald C.]

I'm starting to get that infamous clunk when the rearend gets warm and I'm going to have the posi clutches replaced and the rear-end reshimmed, etc.. Since this does it when the rearend is hot, are there any other reasons for the clunk?

Can anyone give me an estimate of what this should cost? I'll just need a ballpark number because I'll have the U-joints replaced, erc.

Thanks,

Jerry

[Jack H.]

Re: Posi-Traction Clutch Pack replacement cost estimate

You may want to consider just doing a fluid change with the GM posi additive. Sometimes the clunk is just the clutches not slipping consistently, i.e. grabbing then slipping. I would try that first before you spend the money on new clutch packs and R&R.

[Gerald C.]

Re: Posi-Traction Clutch Pack replacement cost estimate

Jack,

I've changed the fluid and put the additive. Still clunks somewhat.

Thanks,

Jerry

[Dick W.]

Re: Posi-Traction Clutch Pack replacement cost estimate

Jack,

I've changed the fluid and put the additive. Still clunks somewhat.

Thanks,

Jerry

Take it to a large parking lot and do about 10-`5 lazy figure 8's. This will lubricate the clutches, and in a lot of cases, stop the chatter

[Joe L.]

Re: Posi-Traction Clutch Pack replacement cost estimate

I'm starting to get that infamous clunk when the rearend gets warm and I'm going to have the posi clutches replaced and the rear-end reshimmed, etc.. Since this does it when the rearend is hot, are there any other reasons for the clunk?

Can anyone give me an estimate of what this should cost? I'll just need a ballpark number because I'll have the U-joints replaced, erc.

Thanks,

Jerry

Jerry------


It might just be the u-joints only and have nothing to do with the posi clutch pack.

[Jim T.]

Re: Posi-Traction Clutch Pack replacement cost estimate

Would another bottle of the GM posi additive be worth a try?

[Gary R.]

Re: Posi-Traction Clutch Pack replacement cost estimate

Sounds like posi chatter. Maybe Joe knows, but the GM additive changed part number and packaging last year. I build a lot of posi's and tune all of them, I never had a posi chatter until I tuned a '69 a few months ago, right about the time I started to get the new posi additive. I was pretty sure the posi was tuned perfectly, I ran the new clutches in on my machine with the additive. I was ready to go through it again until 2 bottles of additive were used and the old parking lot figure 8's done. That solved it, the car was auto crossed and driven hundreds of miles since. So now I use 2 bottles in every diff with a tuned posi. I do not build them with the springs and plates but I suspect it would be worse depending on how the spiders are set up. Do not use the new fiber coated clutches and huge yellow springs, it will be quiet for a time but the fiber is smudging off all the time. Stay with solid steels, just as was used from 1965-1970. If you have more questions let me know or shoot me a PM and I'll go over setting them up with you. I have coached guys through this before.

[Gerald C.]

Re: Posi-Traction Clutch Pack replacement cost estimate

Joe,

Would the U Joints wait until the car gets warm to clunk? Plus, the rear end feels a little "loose" or "squirelly" (if that's a word!) at times. I will try the parking lot exercise, but I'm not sure if that would cure my issue. may try more additive.

Thanks

[Joe L.]

Re: Posi-Traction Clutch Pack replacement cost estimate

Joe,

Would the U Joints wait until the car gets warm to clunk?

Thanks

Gerald------

No, usually u-joint problems are not affected by "warming up".