If the axil ratios are reasonable, not sure what the benefit is to replacing the differential.
As for wheel hop, about a year ago my T100 started to hop when pulling away from a stop. Too much clutch and it really jumps. I thought it might be motor mounts but, they seemed ok. I later found that my right side rear spring was completely broken off right over the axil housing. I assume this is the problem. I got a new set of springs from Alcan Spring in Grand Junction and they are being installed now. I will report back when the work is complete.
From day on the T100 the 2 leaf springs were no good.
I thought the same problem. I have a completely redone leaf pack with even an extra spring in there..still jumps.
Im mostly wanting an entire axle b/c what happened (or what I think happened I should say) is: Due to the axle shaft being shot it eventually galled out the inside of the axle tube, causing it to be out of round. SO no matter how many shafts, bearings or whatever you do it wont ever work right. I cannot figure out any other reason that even toyota themselves cant get the axle seal to stop leaking. Ive replaced it 2x, my buddys shop has doen it 2x and so has toyota. it still leaks. Replaced the shaft 2x now, thought maybe I should buy new not used 2nd time, figured maybe the guy pressed everything wrong..nope.. Every mount is new, springs are redone, etc, etc, etc. There nothing left but the axle. I take the rear shaft off and drive in 4wd it smooths out, I drive in 4wd it smooths out slightly. Put the truck in the air disconnecting the rear shaft and drive it in the air-perfectly fine.
If I spend for an axle and for whatever reason it doesnt work Im trading it in on something.