15178A - SERVICE UPDATE (REVISED PARTS INFORMATION, SERVICE PROCEDURE AND WARRANTY TRANSACTION INFORMATION). THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO PERFORM A DRIVE AUDIT AND, IF NECESSARY, REPLACE THE REACTION/OUTPUT CARRIER ASSEMBLY AND ASSOCIATED PARTS ON CERTAIN 2015 MODEL YEAR CADILLAC ESCALADE, ESCALADE ESV; CHEVROLET SILVERADO LD CREW, SILVERADO LD CREW LTZ, SILVERADO LD EXT LTZ; AND GMC SIERRA LD CREW, SIERRA LD CREW DENALI, SIERRA LD EXT, YUKON, YUKON DENALI, YUKON XL, YUKON XL DENALI VEHICLES EQUIPPED WITH AN 8-SPEED TRANSMISSION (M5U) AND A 6.2L ENGINE (L86). SOME OF THESE VEHICLES MAY EXHIBIT A TRANSMISSION GEAR WHINE NOISE AT 1000-2000 RPM AND BETWEEN 20 MPH (32 KPH) AND 35 MPH (56 KPH).
