Im going to use this Jag XJS powerlock diff in my MGB Sebring, the diff is in good shape other than one of the LSD plates is shot.
I only need one plate, what other axles are these in?, I dont really want to buy a complete set as its rather a lot of money. One other thing, are the Jag IRS Dana & Salisbury units fitted with the same size bearings? thanks
-- moved topic --
Tim, the bearings have different taper angles iirc. A wide range of applications used the power-lok but people confuse it with that other posi.
Jim
If this is Dana 44, use their plates, as-in ebay/etc. ?
Do you have dimensions of the plates?
I rebuilt a SD1 Salisbury LSD using plates from a Dana locker. Actually, I bought a complete NOS locker for less than I could buy the plates!
I still have my old plates and can compare. The Salisbury posi was heavily designed on the Dana - the spider gears are identical enough that they work, and the cross-shafts are longer on the Dana, so can easily be cut down to suit the Salisbury.
Most of the salisbury and dana parts interchange except for the bearings and the side gears. Spline is different on the side gears. Bearings can be mixed and matched to work so that dana parts can be used in the salisbury. Ring bolt size varies but there are bushings available also.
Jim
Thanks for the replys, Ive finally have the unit apart.
Turbodave, I have the sizes now, the plates with the two ears, 86.19mm x 57.76mm,
The plates with the teeth are 84.79 x 51.39mm they have 42 teeth. this was measured with a cheap ebay dgital vernier caliper.
I'll check my plates tonight and will get back with you. First thing that's definitely different is that the SD1 and Dana PowrLok that is of a similar size has four lugs on the plates.
This is a pic I had on my phone of the Dana vs the Salsbury components. You can see the four-lug plates. The plates has the same curvature and thickness, splines, and dia - the only difference was the DANA had squared lugs, the Salsbury was rounded.
POSI2.jpg
There are other, fairly minor differences. For instance you may find the side gears on one have a shoulder which gives it a longer spline and the other doesn't. Most of the parts are interchangeable though. I have not seen the clutches with the rounded tabs I don't think.
I have mixed and matched some parts but try to stay consistent within the carrier if I can. You can set the clutches with up to 120 ft lbs of torque loading which is a little high for an MGB but does work OK. Makes it hard to push by hand in the shop though.
Jim
This is two of the plates from my diff, over here in the Uk I can only find Dana 44 plates listed for jeeps. And they are about twice the price that you pay, so I would want to buy a set from the US & get them sent over, just dont want to get it wrong...
dana44.jpg
Jim, do you think these will work? thanks
https://www.ebay.com/itm/Trac-Lok-Clutch-KIT-Dana-44-Dana-Spicer-Jeep-TJ-YJ-XJ-Wrangler-Cherokee-Wagoneer-/272132206948
One other thing, one of the retaining clips had come out & was in a bad shape, can you get upgraded, stronger clips? or is there anything to help keep them in check? thanks
Those look to me like the right parts. Your old ones don't look too badly worn, what is the most important thing is when you put it together, rig an axle shaft or stub shaft so you can put a torque wrench on it, and see what it takes to turn the side gear. If you are in the 60-120 range it should work just fine. The difference is in the thickness of the stack. I think Jag sets theirs up for 80.
Now that I think about it, the rounded ears and clips are familiar. Don't really remember where I've seen the square tabs but I have seen them somewhere. I think both the Power-Lok and Trac-Lock use the rounded tabs but the Trac-Lock uses fiber friction surfaces. As for the clips, those should be available individually. The clutch plates should as well. Plus if you check with any local axle shop or Jag shop or dealership they should have surplus parts lying around. Dodge also if they work on the old stuff. As much as I appreciate the attraction of new parts this is one place where used parts can sometimes let you dial in the performance you are looking for. Being a light and narrow car, the MG doesn't need the full 120 ft/lbs. I haven't noticed it hurting the cornering, but then I threw out my baseline when I also fitted a different front bar so I can't really say for sure.
Jim
Thats very helpfull thanks, I hope this Jag IRS is worth the bother over a live axle.
It is definitely going to give you a better ride. I don't think you will notice much difference in the cornering characteristics but the tires will stay planted better on uneven surfaces and that will help. The most noticeable difference is going to be the absence of the jolt in the back the stock axle gives you over highway expansion joints. Just that alone can be reason enough.
Jim
Yes good, my only reservation is that Im building this car with a rear mount turbo, and room for the pipes could be a little tricky, but Ive some ideas how Ill go with this et up.
Well having asked on about 5 forums still nothing, I dont fancy chancing sending for a set from the states & finding them to be incorrect not at $150 a time, so Im thinking about welding the plate with a broken ear to a good plate. Not very good but not much else I can do.
You should learn to do a google search.
https://truckandgear.com/yukon-gear-and-axle/yga-yspcg-001.html
https://cppdiesel.com/yukon-gear-and-axle-ypkd44-pc-02-powr-lok-flat-drive-plate-for-dana-44/
Google: Dana 44 power-lok clutch
Jim
Thanks for that, but Ive found many sets on the net, some look identical & some are not, Ive yet to find a set listed for my application.
My problem is, Im in the UK the shipping & import duty makes that US price about double, bad enough if the parts are correct, but very bad if their wrong.....I dont feel at this time I want to chance it.
So you don't think the Dana clutches will fit the Jag Power-Lok? Odd, I've found them to be interchangeable myself.
Jim
I have a Dana 44 trac Lok in my Jag Diff, they were fitted to XJS for 3- 4 years back in the eighties, these dana LSD plates come with a different tooth count on the internal bore, & some have 4 lugs whilst mine has two lugs.Is the diameter the same on all? I dont know, Ive found some that have the same ID tooth count & the same two lug plates, but Ive asked sellers for ID's & OD's but no one has answered me on that.
Trac-Lock and Power-Lok are competitors and the parts are not interchangeable. The Power-Lok is a heavier unit, has twice the number of spiders, uses all steel clutches and has two halves that bolt together with about 8 rather substantial bolts to compress the cone washers. No interchangeable parts.
I've not seen any Power-Lok clutches with 2 ears. That's Trac-Lock stuff.
You might try contacting these guys:
https://www.justdifferentials.com/category-s/2579.htm
Jim
yeah, its Trac lok parts I need thanks
Oh, well those are much more common, you should have no problems finding those parts.
Jim
Well, Ive finally found a company that can supply me a set of plates & clips @ £108/ $143, the seller has stated that I should use an oil additive that they sell, is this required? One other thing, what would you recommend re; oil+ additive? thanks
I use synthetic 75w90 and limited slip additive in my 44. Amsoil or Royal Purple are both good in my opinion.
For a posi, yes. I used to use the GM additive.
The oil additive is to protect the posi clutches and yes, it is required, although many axle gear greases already include them, and there is some argument that synthetic gear greases don't need them. Cost should be in the $5-15 range for about a 4oz bottle. Available anywhere, even car dealerships.
Jim
Thats for all the help on this, the supplier of the plates sells additive @ $18 so Ill buy that too.
QuoteI should use an oil additive that they sell, is this required
Any wet clutch system has to use a friction modifier so that the plates won't stick together. eg. Wet clutches in motorcycles also have to have a friction modifier - my Yamaha, for instance, uses their formula "Yamalube" oil.
$18....wow, a bottle of Ford XL-3 friction modifier in Canada is about 5 - 6 bucks.
Fordfrictionmodifier.JPG
Graham is the engineer here, not me. While posi clutches need to be able to slip when the car is turning, a wet motorcycle clutch is not quite the same. Don't want that clutch to slip when under power.
I have owned motorcycles since 1973. I have never used a motorcycle oil. Motorcycle spec oil has only been around 20 years or so. Wet clutches (motorcycles) do not need special oil. Just do not use any "Energy Conserving" motor oil that may cause clutch slippage.
I find that Rotella T4 (conventional), T5 (blended), or T6 (fully synthetic), all MA/MA2, rated in 15W40 gets it done for most of my bikes.
It doesn't have to be the high dollar stuff to do the job. Ford has used many trac-lock posi units, their additive is fine.
Jim
Quote....I have owned motorcycles since 1973. I have never used a motorcycle oil.
Standard motor oil has never worked in the any of my Yamahas without the clutch packs sticking together .....maybe that Tennessee snake oil has some secret ingredient.
Back in Muscle Car era, the LSD,TracLoc, Sure Grip or Posi required the Special additive to allow the clutches to slip and not try to lock during turning corners. Ford, GM, Chrysler and AMC had their own name for the additive, but all did the same function. Originally; GM used whale oil as their lube. Unsure what others used. EPA changed that and few other things.
Factory Service bulletins noted: Add the special oil when customer complained of noisy (popping) rear end when turning. Once added, you went to parking lot and made circles both directions to mix the lube and lubricate the clutch packs. Usually problem was solved. Ford additive came in 4 fl.oz, and smelled BAD! None of had a pleasant smell. My story and I'M sticking ti it. :-)
QuoteStandard motor oil has never worked in the any of my Yamahas without the clutch packs sticking together
Must be that darn cold weather. Or, you aren't riding hard enough. ;)
Trail riding, street riding, motox & drag racing, I have never had any issues with motorcycle clutches.
For people living in the states be greatfull for the cost of parts, the plates & additive has cost me $174.50.....you lot are spoilt!
A bit late as I haven't been following this, but do Hauser supply these parts?
https://www.hauserracing.com/pages/parts They specialise in axle builds.
Do agree about the shipping and import duty, self-inflicted in my case as I chose to run an American car.
Ivor
Yeah i got the parts from them, I must say it was a PITA to get the plates into the carrier, not a job for some one that does not have some ability. But its looking good, & Im pleased with the outcome, thanks every one for your help!
Yeah, one of the down sides of the trac-lock. But they do a fair job once set up... until the plates wear. The first 10K miles will be good though.
Jim
Is that 10k of hard use or moderate use?
I think I'd have to say moderate but YMMV. With the weight of the MG you could get much more out of it. It is however a steadily decreasing effect and at some point the clutches will need replaced. The thing is, wear will occur even if you never spin a tire.
Jim
I'd no idea their life was so short.
And presumably the wear particles find their way into the bearings.
A viscous lsd like the Nissan R200 that can be fitted to the TR6, seems a better idea. Pity they're not more available.
Ivor
"And presumably the wear particles find their way into the bearings."
That would mainly just be the clutch friction material.
The wear particles don't seem to be a problem, apparently they are small enough and fall to the bottom or get minced by the gears. Personally I like the Power-Lok instead for a number of reasons. Having all steel clutches, they last longer. Having ramps on the cross pin ends they are less dependent on the cup springs to apply, they are easier to assemble, and have twice the number of spider gears. But they do wear also, just not as fast. They can also be heavily preloaded if desired. Of the entire spectrum of less expensive posi units they are probably the best, although some drivers would prefer the Detroit Locker. Moving up in price of course you have your gear type, viscous, and of course on-demand electric or air lockers. The gear type were once considered THE thing but that was before everyone realized that they can't ever transfer 100% torque to the driving wheel. Every design has limitations, you just have to pick the ones you can live with and afford. I'm not sure exactly what the limitations of the viscous ones are, not having driven one, but I suspect heat, and less that 100% load transfer.
Jim
Now having rebuilt this, I can see its not such a big deal to leave the axle in the car & pop out the carrier to replace the plates when its time.
This Dana diff has a 2.88:1 ratio, I do have a salsbury Power Lock unit with a 3.7:1 ratio in as new condition in my spares stash, maybe use that if this 2.88 is not a good match later on.
May want to look for a set of gears around 3.31, I think that will fit the 3.71 carrier but check. Look for a set of original Dana gears as they are harder and will wear longer.
Jim
Ok I note your comments, Jim is your MG at stock ride height? Im ready to set my diff in the car & see your build. Thanks
Tim, I'm not sure which means probably not. I went to some trouble to be able to make the half-shafts the limiting factor rather than the upright bells and to preserve maximum suspension travel. It probably sits about at stock height or maybe a little lower but of course it's also 6" wider.
Jim.
Shame that the How It Was Done page is so behind on Jim's updates to his car.
There is some info in the 340 thread and the roadmaster thread though.
I could submit an updated HIWD but would it ever get posted?
Jim
Jim, Ive seen MG's with jag axles but never looked too close, are you saying with keeping the stock track I'll have to limit the suspension movement?
QuoteI could submit an updated HIWD but would it ever get posted?
I submitted updated HIWD info to Curtis over 2 years ago and still no activity..... suppose that PACCAR is keeping him pretty busy these days.