Don't know if yours is the same as my 2002 model but here are the specs.
Pinion bearing preload - .43 to .51 ft/lbs
Pinion/ ring gear backlash - 0 to .008" (.2 mm)
available pinion shims "A" = .008" (.2 mm)
"B" = .004" (.1 mm)
When I did mine years ago the backlash ended-up OK with the original shims but it's not as critical on this slow-moving vehicle. The preload is more critical, especially if it's not enough and the pinion gear gets a little loose and cocks just a little bit. The last time my diff. went out I just bought the whole chunk new. The ring gear studs are subceptible to breaking in this diff too. Be sure and clean the whole axle housing out if you had a bearing or gear go down badly. I used paint thinner and a blowgun and got it spotless before reassembly. Good luck on the job ....