13346 - Service Update. Inspect the transfer case adapter housing for two specific build codes. If the housing has one of the two codes, dealers are to test drive the vehicle and, if necessary, install a new transfer case adapter housing. The front and rear machined surfaces of the transfer case adapter housing on these vehicles may not be parallel to each other. This could cause harsh downshifts, a "bump" feeling when coasting, or a grinding noise on deceleration. These conditions may be more noticeable in the tow/haul mode and when using engine braking without using the service brakes.
