I have a 2001 Silverado 1500 Z71 with the 5.3 liter engine and the automatic transfer case. It has almost 36k miles.
When I put the transfer case into any 4wd setting (auto, hi, lo) I get a low howling noise from the front of the truck. There is no noise in 2wd. The noise is loudest while accelerating but is also noticable when coasting to a stop. The noise is also louder in 'hi' than in 'auto'. I just bought the truck so I don't know if it has always done this or not.
A Chevy dealer (Cambridge (MA) Chevrolet) replaced a hub which didn't change anything. They wanted to rebuild the differential for $1200 - $1700. Instead, I took it to an independent mechanic and they think the noise is normal transfer case noise. I also had a GMC technician drive the vehicle and he thinks it is normal.
Any advice for me?
Thanks!