lukebas

Figured I would join the forum after reading on here and also I have a few questions if anyone could help. I bought an XJ for cheap and I'm pretty sure it needs a new rear diff, I want to make sure I'm doing the best thing here. My plan was to go to a junkyard and swap the whole rear axle out with a Chrysler 8.25 3.55 ratio.

I wanted to make sure this was the right ratio and will bolt right in, right now I think the jeep has a ford 8.8 rear and not sure about the front, but I think it's stock. It's on 33s as well.

I'll attach some pics and if anyone can chime in I would appreciate it. Not the best but I can get more tomorrow.

cruiser54

Welcome!!

Really, the best way to tell the ratio is pull the rear cover and get the numbers off the ring gear.

If it is 3.55, which is standard on a 4.0 with auto trans, your plan to get one from the junkyard is a good one. Grab the U-bolts also.

lukebas

Thanks, should I get new u bolts? And I was going to do the tire rotation method to find out the ratio a little later today

cruiser54

You could get new. I live in Arizona so I never buy new ones.

Tire method would do fine.

lukebas

I'm hoping it will be accurate. I think the problem is with the locker in the rear. It pops loud when turning slow. The build sheet says 3.55 but the jeep was modified and I got minimum information about what was done.

cruiser54

Better pull the cover.

Or, check the front using the wheel turning method and hope the rear is the same.

lukebas

I got three and a half turns, pretty sure it's a 3.55