8.25 sure grip, with disk brakes.

[olsn500]

So I have been reading that 1st gen Dakotas pre 95 with 5 lug 27 spline axels have the sure grip diff. I also saw at an off road site that they can swap 93-98 Jeep Grand Cherokee rear disk brakes on to an 8.25 rear end.
My thinking is that I could use the 27 spline axels in my 76 Newport, the Newport housing, Dakota differential, and the Cherokee disc brakes.
The disc backing plate does have an issue where you need a bearing spacer, but Crown makes a bearing spacer that lets you use it.
I was using the search function and did discover a thread about using Dakota diffs but with the newer 29 spline axels. Has anyone else tried this or have any recommendations as to how to go about it. I just want to try something different with the car that not 10 people have done.

 

[65sporty]

Sounds like a interesting swap, the 29 spline axles would have to be custom made though I would guess the length to be different.

 

[commando1]

I just want to try something different with the car that not 10 people have done.

I'm getting chills...

 

[70bigblockdodge]

8.25 axles are the same except for the spline count. They are c clip rears, the axle is retained by c clip in the carrier the outboard bearing only aligns it radially, axle will slide in and out of outboard bearing so getting the caliper close should be good enough. Since you will need custom length axles I would try to use the later 29 spline carrier.

 

[jake]

8.25 axles are the same except for the spline count. They are c clip rears, the axle is retained by c clip in the carrier the outboard bearing only aligns it radially, axle will slide in and out of outboard bearing so getting the caliper close should be good enough. Since you will need custom length axles I would try to use the later 29 spline carrier.

Again, you blow me away with your knowledge.

 

[67-Fury]

My moms 97 Jeep Grand Cherokee has rear Disc brakes. When the day comes that either me or my Girlfriend Destroy the Car(It's Inevitable)They will be mine.

 

[1978 NYB]

Let us know how it turns out.

How are you going to regulate brake pressure to the rear? What proportioning valve will work properly?

Plenty of pictures please.

 

[70bigblockdodge]

I did some checking on this on rock auto. Seems the 8.25 is not as popular as you would think they lists lot of 90s jeeps with Dana 35/Dana44 rears, that will not work as easy. I also learned the pass car 8.25 and 9.25 take the same outer bearing so with some creative bracket placement maybe this could be put onto a 9.25 rear also hmmmmmmm.

Back to OP you can get new LSD carrier for a 8.25 and even a tru-trac. Unless you know the history of a cone type carrier or it is really dirt cheap, you might just be better off buying a new unit. This is from someone that is really a cheapskate.

 

[olsn500]

So an update, I have found that this swap is very popular with the jeep guys so finding these backing plates at a reasonable price has been a challenge. Success though, found them for $35 on craigslist with new rotors. Unfortunately he had already parted with the new calipers. These have a ridiculous core fee, so need to scrounge those up next. Then I'll get a new set. Got a 3.55 ring and pinion out of a low mileage wreck, $70.
As for the proportioning valve you need to use the newer Cherokee valve or at least the spring and cap. Rear disk requires different pressures to the rear. I was thinking of trying a stock car valve. You can adjust L/R-F/B with those and they used to be like $12 from Speedway.
Lastly is the sure grip/trac loc, I have found several 29 spline trac locs in the 6 lug Dakotas. I have only found one 5 lug 27 spline but it didn't have the sure grip. Search continues....

Oh and it looks like I won't need a spacer for bearing load on the axel, that's only on the Dana's.

 

[olsn500]

This also might be helpful to other people. This is the compatibility list from Oreilleys for 8.25 posi. There's over 300 different kinds of vehicles that came with a 27 spline 8.25 sure grip. This sure opens up a lot of territory for me to search.

PowerTorque 722B715A - Posi Unit | O'Reilly Auto Parts