Matthew Alvarez

Im pretty sure its leaking but what parts would i get ? its a 2014 F150 STX 5.0 axel code L9

JCR 56

Pinion seal.

PerryB

Yep, pinion seal. It's not an inherently difficult job but it has to be done right. After replacing the seal, the pinion nut has to be returned to exactly the same position it was originally in, or just a couple (and I mean just a couple) degrees tighter. You should use a new crush sleeve, but if you do the "couple degrees more" method, that can be avoided. Use blue lock-tite on the threads. Don't let just any ijjut with an impact gun do this job.

greasyknuckles

if you replace the crush sleeve though, you then need to remove the carrier assy.
so you can set the pinion bearing preload. which I think is 18-26in lbs. need to use a beam type torque wrench, click type won't cut it