1990 Jeep YJ Differential

FRANK6154

MEMBER
1990 JEEP

OK. Two ammateurs here. We went out and bought a used complete rear axle for a 1990 Jeep YJ, staight 6, 136k miles. We tore apart the current dif and tore the guts out (the gears) and installed the one out of the axle we bought. The gears on the part attached the drive line do not seem to be biting into the big gear that drives the rear axles. We get heavy vibration and no traction. Should we switch out the gear that is attached to the driveline as well? Or, should we take this to a pro and if so what should we expect to pay for this service?

All and any help much appreciated!

John

1 Reply

MECHCURT

MEMBER
184 POSTS

Sorry about the late post so hope this helps in some way. Diff's are an art. They are not hard to work on but you do need some experience to make them work properly and noisless. Also to make them last so I would get a book or take it to someone that can do it for you or at least teach you. The gear you are talking about is the Pinion shaft. The ring gear and pinion shaft must run with an exact tolerance of distance apart. You also have to have it shimmed in all the right locations to wear the gears mesh at the proper distance. We do rear in set up's for anywhere from 300 to 500 depending on exactly what we do. Thats usually labor only. Hope this helps Curt