4bolt Rear Differential label number question...

sho_pow · 12-20-2004, 04:06 PM

I have a 90 AWD with a 4bolt rear end that I've had on for about 5,000 miles. Well my center diff blew and I ended up getting it welded and having my tranny rebuilt. Now when I drive the car all for wheels seem to be semi-locking up and rotating at a different rate. I ended up disconnecting my driveshaft and transfer case and I'm running FWD for now. The rear diff seems to run fine with the half shafts still attatched. I don't hear any noises, but I sometimes feel a slight vibration coming from the rear upon initial take off. I know the transfer case isn't seized because I opened it up and everything was fine. I'm pretty sure its the rear diff.

Now after thinking about it I realized that the label number on my rear diff says, "J1H" with Viscous LSD above it. My original 3bolt had an LSD btw. I know that there are other 4bolts with the label "B1H" or "B1G". Is "J1H" for automatic? That would explain why my center diff blew and why my car still struggles to move. I made sure when I bought the rear diff from the guy it was from a manual not an automatic. Can anyone tell me if my 4bolt is for an auto AWD? Thanks for the help!

Louie

GritsnGravy · 12-20-2004, 08:38 PM

The B1G should be the rear diff for your car. The "J" is for automatics. My 91 has a B1G and so should yours. I think the automatics have a different gear ratio. As long as the gear ratio is the same, you should be fine. It should be 3.545 and it shold say on the label. Good luck.

sho_pow · 12-21-2004, 08:57 AM

Ya I figured it was auto. That would make sense why my center diff blew..... Damn seller screwed me over!

Does anyone know if the internals of a 3 bolt can go into an auto 4bolt?

Is there a difference in halfshafts from an auto 4bolt to a manual 4bolt? In otherwords can I use the halfshafts I have right now (from an Auto 4bolt rear diff) and use them on a 4bolt rear diff for a manual car?

Thanks again!