2021 axles

[Corey M]

So we bought our Big Horn in December of last year. We pretty much only used it for pulling the camper and only had 3500 miles when we went on a 3000 mile vacation. Well when we got back , we noticed a clicking noise occasionally when we turned left or right.. so I took it to the dealer and explained the issue. I also mentioned when turning, it seemed like it was in 4wd as you could gear the tires squealing. The dealer called later in the day and told me the factory didn't add an additive to the axles. They drained them, added the additiven and filled then back up. No more clicking or squealing tires. My gas mileage also jumped from 15 mpg to 19mpg!

 

[18CrewDually]

My 2018 does the same after a couple hundred miles at highway speeds, mostly towing. It was really noticeable on this past weeks trip to FL from NJ.
Its definitely the rear axle differential clutches grabbing. It goes away if I let of the throttle on the hard turn and get back on it and the feeling is gone. It happened everytime at the end of an exit ramp, coming from a stop turning hard.
My theory is the oil gets hot and the clutch pack loses the film of lubrication on the clutches. Then when you make the first hard turn under throttle you feel the clutches excessively grabbing. Letting off the throttle unlocks the clutches allowing the oil to wet the clutch faces again and the binding is gone.