Like Iv said before, Im still new at learning about the Axles and other Jeep stuff.
That's why I suggested Eric's book, but you acted like you didn't want to hear it. Are you really looking for help, or just someone who'll agree with ya?
More Questions... What size engine? Auto or Stick? If it's manual, do you get this "dogging", or Bucking, in 1st and 2nd gear too or only high gear?
Differential Gear Ratios are not the same in Automatic and Manual transmissioned Cherokees, so if you get that Rear (from the Auto and you're Stick) you can add another $150, Plus installation, for changing the R/P in the front. The "Type" of Cherokee (Model XJ) that you have was first made in 1984, any part from earlier "Cherokees" won't work! These are called FS (Full Size) Cherokees.
Differentials... Strength wise, if they're both 27 splines, the Dana 35 & Chry 8.25, you'd be wasting your $ on the 8.25, it's actually the weaker (shaft wise) of the two
plus the fact they both use C-Clips, even the Late Model 29 spline shafts. This way when you break an axle, the wheel falls off
I agree with Ted, the 31's are NOT your problem. I ran 31's on my 3.55 geared XJ and I lost a bunch of power (acceleration). I installed 4.11 gears and got it back. Now I'm running 33's and it still runs great, but now I've added a ton of stress to my U-Joints and axle shafts. You
do realize that you went up 5 (
THAT'S FIVE) tire sizes
That's a huge change in Differential gearing! Also, you are now traveling about 11% faster then your speedo says you are, can you spell "SPEEDING TICKET"
Tattoo
Big Point to remember... Everytime you make a change it effects EVERYTHING up, or down, stream.