1. brotherGood

    brotherGood Well-Known Member

    Messages:
    719
    Likes Received:
    84
    Joined:
    Mar 31, 2013
    Location:
    Urbana OH
    Alright, im going to pick up an 8.25 out of a 96 xj on Saturday. 96 was the last year for the 27 spline, and im pretty sure this axle has 3.55 gears. He doesn't know, but what I'm paying for it, its worth the risk..He said he does know it's a good working axle. I'm going in doubting that it'll be sure grip, as most of them aren't from what I've heard, so I'll still be on the hunt for a sure grip for it. I know the perches need flipped, but does anyone know if they're in the same spot, or further one way or another? Also, what kind of jump up do I need as far as Speedo gear.

    Thanks
     
  2. BudW

    BudW Moderator Staff Member

    Messages:
    3,814
    Likes Received:
    1003
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    The differential will either be stamped, engraved or have a tag on it.
    If from an ‘96 Cherokee the tag number will be either: (for rear differential)
    Tag #52098933 3.07 open
    Tag #52069230 3.07 anti-spin
    Tag #52098930 3.55 open
    Tag #52098931 3.55 anti-spin (or Stamp No. 52069336)
    Tag #52098932 4.10 open
    Tag #52070062 or Tag #52069232 or Tag #52069236 4.10 anti-spin.

    I do have a request:
    One you have differential in your possession, can you get some measurements for me, please?
    Drum to drum (distance from where wheel attaches too, on both ends)
    Center of perch to center of perch
    backing plate lip to backing plate lip (a bit harder to get, this measurement would be “if” backing plates and axles were removed - but it can be made with them on).

    If I know what your tire diameter is (or tire size), and your current gear ratio is - I can find out what speedo gear you will need.

    Thank you (so much),
    BudW
     
    Last edited: Jul 28, 2016
  3. BudW

    BudW Moderator Staff Member

    Messages:
    3,814
    Likes Received:
    1003
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    BrotherGood, I forgot to mention. I don’t know the measurements on your Cherokee differential, yet – so can’t comment on it, yet (which is why I wanted to get the measurements from it).

    The measurements for your FMJ is:
    Perch center to perch center is 44.46” (located on bottom of differential tube)
    Flange to flange is 54.34” (where backing plate touches differential)
    Drum to Drum is 58.50”

    If you need to relocate the perches, I would recommend cutting off the old ones (which I suspect are mounted on top of differential tube) and getting new ones to weld on.

    BudW
     
  4. Justwondering

    Justwondering Well-Known Member

    Messages:
    2,762
    Likes Received:
    623
    Joined:
    Aug 7, 2015
    Location:
    North Texas
    BudW
    What's a perch?
     
  5. BudW

    BudW Moderator Staff Member

    Messages:
    3,814
    Likes Received:
    1003
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    Justwondering,
    I call it a perch. Others may call it something else.
    It is a bracket that is welded onto the differential housing and allows a point of contact with the leaf spring.
    Most Chrysler rear wheel drive cars, the perch is on bottom of housing. Most pickups and Jeeps the perch is on top of the housing – for more ground clearance.

    The perches are clocked to the differential yoke. If they are welded on wrong, one can get angled shims to correct the pinion (yoke) angle.
    Diff Perch 1.JPG
    Diff Perch 2.JPG
    Perch.JPG This company calls it a Mounting Seat.

    Did that answer your question?
     
  6. Justwondering

    Justwondering Well-Known Member

    Messages:
    2,762
    Likes Received:
    623
    Joined:
    Aug 7, 2015
    Location:
    North Texas
    thanks..
    I am smarter now ... lol
     
  7. brotherGood

    brotherGood Well-Known Member

    Messages:
    719
    Likes Received:
    84
    Joined:
    Mar 31, 2013
    Location:
    Urbana OH
    I'll get those measurements..I've not seen any concrete swap info yet, so whatever I can do to help I would like to be a part of. All I've seen is the perches needed flipped..I didnt know you could buy new ones though..let alone for so cheap.

    When I get there, I'll pop it open and see if I cant find the numbers. As much as I'd love the Sure Grip in it, if its not there I wont be surprised.

    BTW..my current tire size is 235/75/15 in the rear..unless I go to street slicks or 255/60s..that'll probably be the size I stick with.

    Thanks
     
  8. BudW

    BudW Moderator Staff Member

    Messages:
    3,814
    Likes Received:
    1003
    Joined:
    Mar 4, 2012
    Location:
    Oklahoma City
    For $10-15, it is not even worth saving them.

    I have a large data base on Chrysler differential specs, but no Jeep information, yet.
     
  9. brotherGood

    brotherGood Well-Known Member

    Messages:
    719
    Likes Received:
    84
    Joined:
    Mar 31, 2013
    Location:
    Urbana OH
    Agreed.
     
  10. MoparKidD-4

    MoparKidD-4 Well-Known Member

    Messages:
    114
    Likes Received:
    18
    Joined:
    Feb 21, 2017
    Location:
    Fort Collins, CO
    Any updates on this swap? I'm looking to do the same as Jeep 8.25's are all over the place here in CO (lots of off-road guys upgrading to bigger axles on their XJ Cherokees). I see one on CL right now for $80 and it has the 3.07 ratio I'm looking for as opposed to the more common 3.55; I still want my 5th Ave to be a highway cruiser first and foremost. My question is regarding the springs, I've been reading but haven't seen them for myself... what do you end up doing with all the iso-clamp stuff? Are non-iso shock plates needed?
     
  11. brotherGood

    brotherGood Well-Known Member

    Messages:
    719
    Likes Received:
    84
    Joined:
    Mar 31, 2013
    Location:
    Urbana OH
    I thought I updated this, but evidently I didn't..

    I drove down there to get it, and the guy stood me up. So I gave the money to my dad and he was going to take care of it, and the guy quit answering my calls. When I saw it resisted, I asked about it and he said it had already sold..but his Internet sales person wasn't aware of that...basically a bunch of BS

    I was going to just use my spring setup, just new poly clamps. I think that'll be easier than going to a non isolated setup since I have a rear sway bar.

    For 80 bucks, I'd get it. Double check on the LSD though..not all of them got them.
     
    MoparKidD-4 likes this.