Transfer Case Whining

[MDEVIR]

Purchased used 2019 a few weeks ago w 50K. Snow storms past few days so used 4A and Snow setting getting around town. Been hearing a drive train 'whine' when traveling w slight load around 20 to 30 mph. Brought to local Ford dealer and indicated problem to be: 1) truck has one odd tire which has different tread depth on right rear; and 2) transfer case been 'torn-up/worked-over' trying to compensate for the different circumference tire. Estimate 3 tires are at 7/32" depth and the one odd tire (presume a newer replacement) is at 9/32" tread depth. Dealer said need to replace all 4 tires immediately and then see if transfer case whine goes away. He said it is not likely to go away and will need a new transfer case. Indicated Ford powertrain warranty does not apply as this damage was caused by the odd tire by previous owner.

Questions - is the 2/32" tread depth enough to cause these problems as indicated?

Anyone else had similar experience?

 

[Aerogt01]

What is their reasoning the Tcase is on it's last legs? Unless 4A was used for thousands of miles with tires in that condition I doubt that's the case. Also, depending where the tire is the open diff will likely make up a lot of the slack anyway.

Otherwise, it is generally not recommended to run different size tires. Yes, it could eventually do damage - I'd just ask if they can just shave the 9/32 tire. But my 4A makes a bit more noise than 2H brand new, and the always-on 4A on the Jeep makes an audible drivetrain whine at all times unless coasting. I've just learned to ignore it.

 

[MDEVIR]

Update - Dealer stated the odd tire was 1/2-in different in height and hence vehicle needed 4 new tires. 4 new tires were installed (Uniroyal Tire Paws) dealer choice - and did solve the drive train noise. Tire cost was p/u'd by Enterprise Car Sales. Based on this result and the inspection dealer indicated transfer case is fine and powertrain warranty is intact. I was happy to hear this outcome!

 

[Deadman]

Thats a big difference in tire. That one tire was trying to go over an inch and a half farther ahead of the normal sized tires EVERY rotation of the axle. I'm amazed there isn't more damage.