Rear axle locks up going forward

KRAZY4X4S

MEMBER
1999 FORD F-350
7.3L
V8
TURBO
4WD
MANUAL
270,000 MILES

My axle will free roll in reverse but it locks up going forward. I had pulled the rear pinion to replace it due to just throwing a u-joint on the rear. Could something have separated in the differential when the pinion was out? Have not got a chance to tear the cover off to look inside yet, but was wondering what to maybe look for. I know it is the rear axle because the driveshaft is not in it and we jacked the rear tires off the ground to double check it and the spin freely backwards. However, rolling them forward it locks up. I believe it is a limited slip differential.

1 Reply

HMAC300

MECHANIC
48,601 POSTS

From your description I assume you have pulled the part in picture and replaced it. I think you may have not torqued the nut down far enough and pinion will spin one way but not another or is binding. If drive shaft is still out see if you have any play pulling pinion forward to back there should be very little if any. If there is tighten nut up more and make sure it will spin freely in both directions because if you get to tight you will put to much pressure on bearings and will need a rebuild.

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