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Are all four tires the same brand and size?
Yes, good tires, maybe 4,500 miles.
thank you - in my research, there is a lot of information regarding the encoder motor going bad. Do you think this is a possiblity or most likely the viscous coupling. thanks again.
There are two different types of all wheel drive systems used on the Bravada. If you have the Smart Trak option (should say that on the dash) then yours has the encoder motor that engages an internal clutch pack and the encoder would be more likely.
If you do not have the smart trak option then the viscous coupling would be the faulty part.