Hi everybody 👋🏻. Long time listener, first time caller.

Ive been having a shudder issue for a couple years now. It happens only when cruising at speed 55 plus, RPM 1800-2100 ish, and while encountering only a slight load like uphill, headwind, or light acceleration.
2013 FX4 eco boost, super crew, tow package, 6.5’ bed if that helps.

I’ve been reading these type of threads for the couple years and have not seen one that had found the cause of a remedy. I finally had time to drop my truck off at the dealer again and I’m sort of skeptical of what they’re saying.

Their story is that it is the differential clutch on the locking rear ended causing the differential to lock up and cause this condition. And they want $1700 to replace the clutch pack. I don’t know much about rearends, but I thought a failed clutch would cause it to not engage? Can it cause the diff to lock?

thanks in advance for your time and answers. I so desperately want this shudder fixed but I’m skeptical that this is the cause.

 

A clutch pack will manifest during low speed turns. It won't make any noise going straight because there's no speed differential between the axles. If you're hearing something while going straight and at higher speeds, you probably have carried bearings failing.

 

Based on what little Ive read so far, that’s what I thought. The symptoms don’t match what they’re telling me. And they said the bearings are good. It does happen while going straight.

 

The locker rear end is open with no clutch packs unlike the limited slip differential.

 

Sounds like their tryna hose ya. I’d take it to an axle shop and see what they say. Or another dealer