2017 F250 super duty diesel 4 door 4WD around 75000 miles

Forgive me for the long post. I’ve been chasing a noise for at least 2-3 years now. The best way to describe it is when driving and you veer off the road and hit the rumble strips and you get that rumbling sound. That said its only noticeable upon de-acceleration at speeds above 60 mph it has progressively gotten worse over time.

Repair 1- brakes and new calibers

Repair 2 – re-balancing and checking tires.

Repair 3 – new U Joints

Repair 3 – Repaired vacuum lines for the EWI, one of the lines was broke so I replaced the line and the solenoid

My mechanical level and tool limitation required I take it to a shop VERY Reluctantly.

Mechanic said it’s the bearings. Removes both differential covers. Note nothing internal had been touched since the truck came off the lot. Rear was a little black but the front had metal in the gear oil, and 1/8th to ¼ chunks of metal was found in the front. So, all the bearings and races were removed only showed a little wear. Unknown where the metal came from, maybe factory(?).

Since the mechanic was worried where the metal came from, he called in a drive train specialist that went through the front end and had no idea where the metal came from but added that if he was chasing a sound more than likely it was the ring and pinion on the rear.

Repair 4 – All bearings and races in the front and back as well as the ring and pinion in rear.

So, all bearing, races, seals and new ring a pinion in the back were replaced, everything back together still making the noise but now the death wobble is back and now the actuators on the driver’s side is not engaging. My frustration level is elevated at this point. I assume they fixed the actuator and the death wobble since today they said they are removing the transfer case to see if its in there. The gear oil looked fine.

This is why I didn’t want to take it to a shop I had an eerie feeling they would chase the sound at my expense however, they are covering the costs of diagnosing.

Any suggestions, this is starting to cost a whole lot more, not only in money for the mechanical but costs in time without the truck since I rely on it for my business.

 

Exhaust brake leak?
On gas 90's F250, I had a heat shield it the drive shaft that sounded like washboard.

 

When the transfer case was taken apart it appears the drive sprocket on the output shaft to the rear was damaged and wallowed out a couple thousands of an inch. new sprocket ordered, so we'll see. I just feel like we are throwing parts at it at this point...