Okay,I picked up a 1989 10.25 differntial with a open carrier and want to put a posi in it and change the gears. The posi units are supposed to be the same from 1985 to 1997 as far as my research told me. The only difference I knew of was in the 2 differnt ring and pinion assemblies (the 1993 up having a longer pinion shaft that required a different yoke to compensate) and I was told as long as you had the newer yoke for the newer model (1993 up) ring and pinion that could be insralled in any 10.25 housing. Now when we try to put the new posi with the post 1993 ring and pinon assy in the 1989 housing the pinion flattens right out and rubs on the posi housing. Is there a problem that you cannot use the post 1993 gears in the pre 1992 housings period?:homer:
http://img.photobucket.com/albums/v639/mgawat/rubbingdifferntial.jpg

I have and 86 10.25 and had no problem with the updated gear set in mine. You should call west coast diff. They have been a great help for me and for all my parts stuff.

thank-you...do you have the website link?

thanks anyway...I already have it
http://www.differentials.com/

newer style long yoke and long pinion fits and works fine

the reason for the changeover was because the older 10.25 pinions didn't have enough spline engagement in the yoke and the pinion nuts would loosen off resulting in the pinion gear dropping down into the diff. all the aftermarket gear sets are long yoke style as well.

that's what my prior research had tol me...I just wanted to make sure there wasn't a problem I didn't know about.