1990 Ford Bronco Rear End Noise and Malfunction

CBRACKEN

MEMBER
1990 FORD BRONCO
V8
4WD
AUTOMATIC
135,000 MILES

Hello, I have a 90 fullsize bronco with an 5.8, $wheel drive and and auto trans. My rear diff that is having the trouble is an ford 8.8 with 3.73's and supposedly a fatory limited slip or whatever ford would offer of that type. While driving up a not so steep hill in 2 wheel drive, the truck stopped moving and started grinding very loud. I was able to get home with the front wheels engaged. After a little experimentation if you will, I have discoverd that if I put the vehicle in drive, and let off the brake (at idle) the truck will start to move forward, but after a foot, it stps and the gears grind in the rear end. My father had a used rear end put in 6 months before. I dont would liket o buy the parts for it but dont know which ones to buy, if its safe to buy used, and what the parts are called. If possible id like to put a posi in the diff, but dont know what parts or assembly to buy.

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

Yo are better off buying a whole rear end at the bone yard, rebuilding a limited slip(POSI) rear end requires special tools and knowledge, You will NOT get it right on the first try! Wont hurt to pull the cover and check it out. If you have the one without a cover on the back, use a slide hammer to pull the axles, and remove the driveshaft, then open it up. If buying a complete unit, just tell Junk man what it's going in and they will pick the right one for you. There should be an ID tag on the rear axle.