I got one in my 91, and I tell ya what.... It was the best investment I have made to this rig, hands down! I have been super rough on it, I use my rig as a skidder at my woodlot, and have had 0 problems with the locker. I prolly have about 25k miles on it, most of which is highway.
Do some searching, there are endless threads on the subject here on yt.



