Moparts

8 3/4 powr-lok too tight?

Posted By: MoonshineMattK

8 3/4 powr-lok too tight? - 06/22/22 08:18 PM

Hello,

Last year we installed a powr-lok in a customers 8 3/4. He is complaining it is too tight and doesn't slip enough in tight turns - Gas stations, parking lots, etc. He hears a clunking sound.

Is anyone familiar with this? I have powr-loks in both my chargers and have noticed the inside wheel slide when turning sharp but nothing I thought was a problem. My customers car has a street lynx rear suspension and I'm wondering if the rod ends on the 4 link amplify when the tire drags at slow speed and cause a clunk?

Thanks, Matt
Posted By: ZIPPY

Re: 8 3/4 powr-lok too tight? - 06/22/22 08:26 PM

Mine was crazy tight after I rebuilt it. I had to use a little extra additive and go out and drive some figure 8s to make it stop banging around turns.
Posted By: an8sec70cuda

Re: 8 3/4 powr-lok too tight? - 06/22/22 08:31 PM

Originally Posted by ZIPPY
Mine was crazy tight after I rebuilt it. I had to use a little extra additive and go out and drive some figure 8s to make it stop banging around turns.

I've only rebuilt one powr-lok for a Dana 60, but had the same result. Had to use the Ford friction additive Dr. Diff recommended and drive it some. It's fine now.
Posted By: MoonshineMattK

Re: 8 3/4 powr-lok too tight? - 06/22/22 08:33 PM

Thanks. We used the ford lube Dr Diff recommended.

I'll have him run some figure 8s too. Good idea.
Posted By: fourgearsavoy

Re: 8 3/4 powr-lok too tight? - 06/23/22 01:51 AM

Some of the rebuild kits out there use all thick plates and that would be too tight and the plates don't slip like they should. I usually re-use a few of the old thin plates when I rebuild one and it works perfectly.
Gus beer
Posted By: MoonshineMattK

Re: 8 3/4 powr-lok too tight? - 06/24/22 03:06 PM

Originally Posted by fourgearsavoy
Some of the rebuild kits out there use all thick plates and that would be too tight and the plates don't slip like they should. I usually re-use a few of the old thin plates when I rebuild one and it works perfectly.
Gus beer


This unit was from Dr Diff
Does he use thicker plates you describe?
Posted By: John_Kunkel

Re: 8 3/4 powr-lok too tight? - 06/24/22 04:52 PM

Dr Diff sells two clutch kits, one for factory and another for aftermarket. If you're not sure which one you had.................
Posted By: MoonshineMattK

Re: 8 3/4 powr-lok too tight? - 06/27/22 02:13 AM

Originally Posted by John_Kunkel
Dr Diff sells two clutch kits, one for factory and another for aftermarket. If you're not sure which one you had.................


did not buy a rebuild kit. Bought a whole new power-lok
Posted By: MoonshineMattK

Re: 8 3/4 powr-lok too tight? - 06/27/22 02:19 AM

Been a couple years but I believe this is the unit

https://www.doctordiff.com/8-3-4-clutch-type-sure-grip-powr-lok.html

My question is:

He hears a clunk in short turns. I don't think its the power-lok. I think its the street lynx suspension. Because the suspension is 4link with rod ends there is not the usual thick rubber insulation. The only thing I can think is that the inside tire drags when he turns sharp. If that tire bounces a bit and unloads/loads the suspension it might make the bang/clunk he's hearing.

Both my cars with power-lok 8 3/4 axles drag the tire on tight turns. But they never bang or clunk.
Posted By: MoonshineMattK

Re: 8 3/4 powr-lok too tight? - 06/27/22 02:20 AM

I just don't see how the power-lok could make a clunk sound. There's nothing in it to clunk.
Posted By: Pacnorthcuda

Re: 8 3/4 powr-lok too tight? - 06/27/22 02:48 AM

Originally Posted by MoonshineMattK
I just don't see how the power-lok could make a clunk sound. There's nothing in it to clunk.


They clunk when the clutch packs bind up until the force applied overcomes the bind and then they release, somewhat violently. Rather than a smooth ‘limited slip’.
Posted By: fourgearsavoy

Re: 8 3/4 powr-lok too tight? - 06/27/22 12:57 PM

Originally Posted by MoonshineMattK
Originally Posted by John_Kunkel
Dr Diff sells two clutch kits, one for factory and another for aftermarket. If you're not sure which one you had.................


did not buy a rebuild kit. Bought a whole new power-lok


Not the first time I've heard of this condition with a "new" Power-Lock unit. They are simply set up too tight from the factory IMHO twocents

Gus beer
Posted By: Cab_Burge

Re: 8 3/4 powr-lok too tight? - 06/27/22 04:46 PM

Originally Posted by fourgearsavoy
Originally Posted by MoonshineMattK
Originally Posted by John_Kunkel
Dr Diff sells two clutch kits, one for factory and another for aftermarket. If you're not sure which one you had.................


did not buy a rebuild kit. Bought a whole new power-lok


Not the first time I've heard of this condition with a "new" Power-Lock unit. They are simply set up too tight from the factory IMHO twocents

Gus beer
iagree
I sold one to a customer of mine that is a lawyer, he had it removed and replaced with gear type posi due to it almost making his 1967 Plymouth 440 powered GTX convertible go into the ditch across the street turning at a corner making a 90-degree right hand turn at or slower than 5 MPH:: puke: shruggy
I'm wondering if doing several hard burn outs might loosen them up some to make them like the stock clutch type posi are? work
Posted By: 500ciDuster

Re: 8 3/4 powr-lok too tight? - 07/03/22 07:53 PM

I used to run dana 44 clutches so they would act that way, they were a tad thicker
© 2024 Moparts Forums