I just bought an Auburn posi unit used, with low miles. It is however for an 98- model and won't fit my 1999. It is still a 8.5 30 spline, so as far as I can gather all I need to do is order a set of carrier bearings that fit the 99+ and install them on the Auburn diff, is this correct? If so, I have a few questions, are Timken bearings the best to use? Also, do the bearings only fit one brand; meaning do i have to buy a certain set of bearings to fit it because it's an Auburn? Does anyone have the part number for the bearings I need? I will also be installing 4.10's so would it be better to just get this all in one kit?

 

I'm using Federal Mogal bearings.

Oreilly's had one bearing and one race, they can order the other and have it the same day.

bearing - LM603049
race- LM603012

 

and this will fit my 1999 2wd correct?

 

That should fit your 99 10 bolt rear carrier. 99+ had larger carrier bearings, those part numbers are for the larger ones - trust me I just bought my second set this weekend.