I have a 98 f150 with 105k miles on it. Replaced the LS diff at 53k, (split it in half), and now when I take a corner, it makes a groaning noise. Only happens in one direction (right turns), and it's louder at higher speeds. Also, I can pull on the rear tire, and it moves a little. Is it bearings or that c-clip?

Already spent 1600 on the rearend, don't want to do it again. I'll buy a currie 9 inch this time.

98 F150 4 x 4 Reg Cab Short bed Off-Road
4.6 V-8
5 speed
K & N FIPK kit
Custom Exhaust
Sony and Boston Acoustics soundsystem

 

Sounds like it could be the clutchs getting worn out. You can have the carrier pulled and rebuilt if thats the case. Its not that expensive or hard.

 

Was friction modifier added to your gear oil, or did your oil (such as Amsoil) already have it? If so you could try adding a bit more friction modifier.

 

ps73, would they wear out in 52k miles? When the LS broke, I replaced everytrhing but the axles. As for friction modiifer, I don't know what is in there. But I'll check it out.

It's been a great truck, but I wish Ford stayed with the good old 9".

 

They could wear out in that many miles depending how much friction modifier they added when they rebuilt the diff.