I have a 2004 F150 with a 3.55 ls rear that has the low speed turning chatter that TSB 06-4-4 fixes.. Unfortunately, I bought my truck after the 36,000 warranty and I can only imagine it would be $500+ to get this service done out of warranty?? (I dont know this for sure)

My question is, I would also like to upgrade my 3.55 to a 4.10 for better towing and was wondering if they would have to replace the clutch packs anyway when swaping out the gears (I dont know extactly how that works)

If this is true, I can justify swapping gears...

Any advise???

 

No a ratio change really has nothing to do with rear wheel chatter. Since you have a limited slip axle. The chatter is from the clutch pacs not releasing as needed. You can try adding LS friction modifier, if that doesn't work a clutch pack change out is required. So if you still want to change the ratio get the clutches done at the same time.

 

Ah, so if I were to have the gear ratio changed, getting the clutch packs replaced would be a very inexpensive extra that they could do while the diff was open?

 

Should save a little on labor rate.