Well I brought my roommates 2000 f150 into the dealership i'm interning at for school and it ran him just under $600 with my work rates(if it was my truck i would have done it myself after work). He got the clutch packs replaced.

 

The friction modifier helped a great deal. The noise has changed from very noticeable to barely noticeable. I'll look into changing or adjusting the clutch plates myself when it gets worse. Thanks for the info on having a dealer replace them.

 

I'll have to see if this TSB applies to my 2001 Screw...brought it to the dealer for the same problem and they just kept adding friction modifier....still does it once in a while...she's not under warranty anymore, so i'm sure their story will now be "oh yes, you need the gear and pinion and diff clutch packs"

 

I just bought the lube and modifier from the dealership. $74Cdn and change!! I still need to change it though. After this weekend I will have it done. I sure hope this solves the problem. I don't like spending that kind of money just to drain it out again.

 

Procrastinator I am. I still have not changed the diff fluid. That stuff costs a fortune. Should I just try the friction modifier first before I pull the cover?

 

I have a similar problem on my '97, except it seems to do it coasting vice powered. I recently changed the fluid w/friction modifier. What next?

 

Update, the modifier seems to have worked itself in fully and I no longer feel or hear anything from the differential. I haul a camper and take it easy starting out with no noise, or empty I can floor it with no noise.


Mcanik, I would suggest changing the fluid also to be sure. $75 is a lot of money but not much more than a tank full of gas.

Joe, sorry no help here.

 

I used the Amsoil gear oil, at like $10/qt...well worth the $30.

 

I just looked up the TSB. As part of the kit, it has a ring and pinion change. Anyone know why? That seems odd to me, they usually don't go bad.

 

My 2003 SuperCrew 2wd with about 36000 miles has this rear end sound and shuddering feeling while turning under power described in this thread. I have the limited slip rear end also, but not sure which ratio. How do I go about adding the viscosity modifier, and do I have to drain out an equal amount of fluid for what I add so as not to overfill the unit? Also, what are the long term possiblities if I continue with my current course of action, which has been live with it and ignore it. Advise appreciated and thanks.

 

me dealer simply added the 4oz of modifier, didn't help for long. my clutch packs will need to be replaced. still unsure if that's something i'm tackling or the dealer. I have the 3.55 LS rear end. From what i've read on this site, if you continue on your course, nothing "bad" will happen IF your clutch packs are already on the way out the door. mine started at like 25k miles and i'm at 105k now.