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Powr-Loc expert needed

This may sound a bit strange but it does work.....if you can't find the additive, STP will do the job too. Before someone wants to 'red X' that comment, I've been doing this kind of stuff for over 30 years. Right now my (now belongs to the X) 2000 Durango has had STP in the rear end since it was only a couple of years old and it's been doing just fine. It has a Trac Lok in it but it still uses clutches but imo, it's a pile of crap vs the PL. Contact Dr Diff for his 'expert' advice but I'm thinking he's going to tell you to take it apart and see what things look like inside. It would be the same thing I would say too.
 
Here’s my advice. Don’t touch anything. I’m sure it’s just fine inside. Add the Fird additive (misspelled on purpose) along with your diff fluid. Go do a bunch of figure 8’s in both directions. Then go driving, making left/right turns. Not hearing any noise, tires not scrubbing while turning? Awesome! Your set.

Most people don’t know enough about differentials to mess with them. So I’d bet it’s ok inside. I don’t know of any website that would show how adjust the clutch packs.
 
Here’s my advice. Don’t touch anything. I’m sure it’s just fine inside. Add the Fird additive (misspelled on purpose) along with your diff fluid. Go do a bunch of figure 8’s in both directions. Then go driving, making left/right turns. Not hearing any noise, tires not scrubbing while turning? Awesome! Your set.

Most people don’t know enough about differentials to mess with them. So I’d bet it’s ok inside. I don’t know of any website that would show how adjust the clutch packs.
There is no 'adjustments' that you can make to one.....just different thickness plates and you got to take it apart to change any of that.
 
You can swap the plates/dishes around to make it engage/lock up quicker or slower.
 
learned something interesting today. Probably should have known this but I'll pass it along for adding to the mental rolodex. In a Powr-Loc LSD the clutch packs are the same regardless of the number of splines on the axle. So now I have satisfied my learn something new every day rule.

Steve
 
learned something interesting today. Probably should have known this but I'll pass it along for adding to the mental rolodex. In a Powr-Loc LSD the clutch packs are the same regardless of the number of splines on the axle. So now I have satisfied my learn something new every day rule.

Steve
Yup....have never seen one that had a different clutch pack set up. Like I mention earlier, you can get different splines in the diff including a one piece setup. Dr Diff sells them the one piece ones.
 
Well, I added a 4oz bottle of GM friction modifier to my fresh lube. Drove about 10 miles on local roads to warm everything up and then went to a local High School parking lot and did at least 20 figure 8 turns at full right / left turn. Did about 5 360 turns in reverse in the middle of the figure 8's. Tires protested by screeching most of the time. If I did larger figure 8's there was less screeching. Overall little to no difference. This diff is set up really tight. I have read that if one bottle of the GM modifier doesn't do the trick to add another. Which I will do tomorrow.

Also when I was under the car I looked for some markings to determine what brand the housing is. Turns out it is a Strange S60.

Steve
 
You used the GM crap? Why? No Fird dealers around you? Gm never had an all clutch posi, it’s not gonna work as well as the Fird stuff.
 
Hmmmm. I got the GM stuff based on reading a bunch of threads on the matter and it seemed like more guys liked the GM brand. I can Get the Ford stuff easy enough. I thought the GM Positraction units were a clutch design...Not so?

To switch to the ford stuff do I need to drain and flush everything or can I just add it as it is?

Steve
 
Don’t drain what ya got in there, just add the Fird stuff.

Gm posi’s used springs, can’t take a huge amount of torque.
 
Get 2 bottles, pour 1 in and go do figure 8’s, still making noise, pour 2nd bottle in and repeat. Noise gone? Enjoy. Noise still there, time to come apart and check it out.
 
5.7 is right on the money, the GM parts and the "posi" additive are completely different than the Power Lok. That's why the lube that has the "posi" additive already in it doesn't work with the Power Lok. "Back in the day" the Mopar additive worked the same as the Ford version. I'm not sure if the current Mopar limited slip additive works since the Power Loks are not used any more. The Ford stuff will likely cure your problem. Had the same issue in the '70's & the correct additive cured it.
 
So I wound up putting (2) 4oz bottles of the Ford friction modifier in the axle and did a bunch of figure 8's. I'd say it is a little better. During the figure 8's the tires still squawk a little. But when doing a full turn backing up maneuver at idle speed there was quite a bit less of the feeling of having the parking brake on. I think I'm going to live with it for a while and see if it will continue to improve.

Also, I managed to get the foul smelling Ford stuff in the axle without spilling a drop and stinking up the garage or me.

Thanks to all for the help and advice on this:thankyou:

Steve
 
As you drive, the additive will work it’s way in between the clutches and will get better when going around corners.

Glad it’s working out for ya.
 
The ford bottles that I bought were 8oz each, the guy that rebuilt the rear said to use both of them. It's not in the car yet so I haven't tested
 
8oz bottles? This is the stuff I'm using. Ford friction modifier xl3 (4oz bottles)
Steve
friction modifier.jpg
 
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