Powr-Loc expert needed

[Hemi Steve]

I'm new to this forum as I have an E body 73 Cuda with a 528 Hemi. I did not build this car so I'm slowly working through the details of the car. I have had the car for about 2 years now and am not happy with the rear axle. I have believed that it has a locker in it because of the way it drives. my big issue is slow tight turns where the tires squawk and skid. I also get a click as I enter a turn at normal driving speed. I have attributed that sound to a locker unlocking. I've never had a locker so it turns out I have been misinterpreting the behavior and sounds. I have decided to change the "locker" to a limited slip to deal with the tire scrubbing and squawking. So to order a Truetrack I needed to know how many splines the axle shafts have. I pulled an axle and was very surprised to find they are 23 spline. It took a lot of searching to find that there are no Truetrack's, lockers or spools that use 23 spline axles. The axle housing is likely a Strange S60 (possibly a Moser...not totally sure as I don't know how to tell the difference). I believe it is a Strange or Moser because a true Dana would have the build date and BOM number stamped on the right tube and the numerals 60 cast into the lower right gusset. My axle housing has none of that. This morning I pulled the cover off to see what's in there. It turns out it is a Powr-Lok with a date stamp 10 1 68 A and a part number 25124 X. That decodes to a 23 spline Powr-Lok that was apparently used in trucks and B body Hemis and 440's in the late 60's.

So, my question is does a Powr-Loc behave as I described or is there a problem requiring a rebuild? Or is the Powr-Loc a POS?

Steve

 

[davek]

I would Call Doc Diff if no one can answer you can email him also. http://www.doctordiff.com/ He helped me with my questions ,he knows his mopars. Do you have a Dana or 8 3/4 I have had both and never had that problem.

 

[Ironbuilt]

Welcome from North Carolina. Did someone weld the gears to make it a "locker"? Pics would be helpful.

 

[Hemi Steve]

I would Call Doc Diff if no one can answer you can email him also. http://www.doctordiff.com/ He helped me with my questions ,he knows his mopars. Do you have a Dana or 8 3/4 I have had both and never had that problem.

It is a Dana 60 (strange S50 housing with the Powr-Loc)

Steve

 

[Ironbuilt]

It is a Dana 60 (strange S50 housing with the Powr-Loc)

Steve

 

[Hemi Steve]

In my youth, welding the gears in an open diff was common as were the missing tooth spider gears. This carrier is very difficult to see the gears let alone weld them.

Steve

 

[Ironbuilt]

In my youth, welding the gears in an open diff was common as were the missing tooth spider gears. This carrier is very difficult to see the gears let alone weld them.

Steve

Something is causing the "short wheel" not to give on a turn. It is most likely internal.

 

[5.7 hemi]

Before you pull it out to inspect, get 2 bottle of the Fird additive. Pour in just 1 bottle, they are either 4oz or 8oz, don’t remember. Now go do a bunch of figure eights in both directions. If it starts to get quieter, keep doing them. If after a **** load of figure eights it hasn’t gone quiet, add the other bottle. Continue with the 8’s. Should be damn quiet at this point. If not, now it’s time to pull the power lok. Take a backlash reading before hand and then yank it out.

Mark the case halves, open it up and check the clutch pack, your looking for anything that is torn, galled, broken etc.. All good? Soak the clutch packs in the more Fird additive over night and reassemble, following the order they go in, button everything together, fill with fresh diff lube, add 1 bottle of the Fird additive and go figure 8’s.

 

[Ironbuilt]

Before you pull it out to inspect, get 2 bottle of the Fird additive. Pour in just 1 bottle, they are either 4oz or 8oz, don’t remember. Now go do a bunch of figure eights in both directions. If it starts to get quieter, keep doing them. If after a **** load of figure eights it hasn’t gone quiet, add the other bottle. Continue with the 8’s. Should be damn quiet at this point. If not, now it’s time to pull the power lok. Take a backlash reading before hand and then yank it out.

Mark the case halves, open it up and check the clutch pack, your looking for anything that is torn, galled, broken etc.. All good? Soak the clutch packs in the more Fird additive over night and reassemble, following the order they go in, button everything together, fill with fresh diff lube, add 1 bottle of the Fird additive and go figure 8’s.

Hate to sound naive but what is "Fird additive"?

 

[5.7 hemi]

Ford, I just misspell it on purpose.

 

[Fran Blacker]

Welcome. No it sounds bad. If the additive doesn't work it's coming apart. You see 23 spline P/L's on ebay but don't hold your breath. If it can't be repaired you might want to jump to better axles. more splines.
To the best of my knowledge 23 spline axles only came in b bodies. So if you use your housing measure twice before ordering parts.

 

[Hemi Steve]

Lots of good advice here. Why Ford friction modifier instead of GM or other?? Is there some design feature in a Powr-loc that allows for changing how "tight" it is?

Steve

 

[5.7 hemi]

It’s better than the other 2. If you got another set of clutches you could “tune” it to your liking.

 

[1967coronet440]

@Cranky

 

[Cranky]

It would sure be nice to see a pic of what's inside once the rear cover is off. Also, you can swap out the side gears (the ones with the splines) to update it to at least 30 spline or even 35 spline instead of swapping out the whole LSD unit. It if is indeed a PL and it's doing all that, then it needs to be looked at. There are pics online that show how the clutches should be stacked and I think Dr Diff has a pic on his site. He can sure tell you how they should be too....

 

[5.7 hemi]

He also has the new side gears with the cross if needed.

Please post a pic, curious minds want to know!

 

[Hemi Steve]

Ok, Here are some pictures. I took them mainly to save the numbers stamped on the case and ring gear. there are a couple of pictures of the cross shaft ends and the "windows in the case. Not much to see.

5.7 Hemi:
What do you mean tune it to my liking. The clutch stack illustration on Dr.Diff site just shows the order of the clutch parts. I see no way to adjust anything.

Also, peeking through the openings I couldn't see any evidence of the spider gears being welded. I suppose they could be but I couldn't see.

I was thinking that maybe the clutch packs could be shimmed so tight before the case half's are bolted together that it would act like a spool but I don't see any adjustment shims. Looks like everything depends on the cone shaped spring rings.

When I put everything back together I didn't have any posi lube to put in with the diff lube. I'll get some tomorrow and try the figure eight turning until the cops arrest me on suspicion of being a lunatic.

Steve

 

[Cranky]

Looks like a Powr-Lok to me. If the clutches are too tight, it can act the way you are talking about. I know that a thinner shim plate (not a clutch plate) is made for the 8 3/4 PL but not sure about the 60. Dr Diff should know about that. Sounds like someone swapped out the 8 3/4 that was in the Cuda and stuck in a B body 60. A measurement will tell you if it's a B body housing. A cast #60 should be on the right side gusset looking from the back. It's not there? Any evidence of someone grinding it off? Just hard to believe someone bought an S-60 and filled it with older technology 23 spline unit and axles but I've seen stranger stuff happen. Also, I'm not sure what an S-60 uses for bearing cap screws but a stock unit shouldn't have socket heads on it....

 

[5.7 hemi]

You can move the clutch plates and discs around to have it act like a spool or engage when more torque of the engine.

You said you didn’t put in the additive, that’s a no no! Let us know how it’s doing after you pour in a bottle of the additive.

 

[Hemi Steve]

I know. I didn't have the posi lube because I was expecting a spool or locker. I haven't driven it without the posi lube which as I said I'll get tomorrow.

So the guy who put this together could have set it up to behave like a spool and not weld the spiders? Do you know of a site that would describe how to do that?