GMC: 2020: Sierra 3500 HD AT4, 6.6L Eng VIN Y

This is a LEMON manual, retrieved in 2025.

• Repair and Diagnosis
• Repair and Diagnosis, all links on one page (may load slowly, but easier to search)
• Labor Times
• Download .zip for offline use

This manual is identical to the manual for the following model variants, except for possibly the "Labor Times", "Fluids", and "Tire Fitment" pages:

• Sierra 3500 HD Base, 2D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD Base, 2D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD Base, 2D Pickup, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD Base, 2D Pickup, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD Base, 4D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD Base, 4D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD Base, 4D Pickup Crew Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD Base, 4D Pickup Crew Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD Base, 4D Pickup Extra Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD Base, 4D Pickup Extra Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD Denali, 6.6L Eng VIN Y
• Sierra 3500 HD SLE, 2D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD SLE, 2D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD SLE, 2D Pickup, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD SLE, 2D Pickup, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD SLE, 4D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD SLE, 4D Cab Chassis, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD SLE, 4D Pickup Crew Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD SLE, 4D Pickup Crew Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD SLE, 4D Pickup Extra Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGM
• Sierra 3500 HD SLE, 4D Pickup Extra Cab, 6.6L Eng VIN Y, 4WD, Automatic T/Case Control, Trans Mfr CD 10L1000/MGU
• Sierra 3500 HD SLT, 6.6L Eng VIN Y, 4WD