GM

GM is a vehicle make rather than a supplier brand. This archive collects the drivetrain units we stock for General Motors vehicles: remanufactured transfer cases, manual transmissions and differentials, listed by unit code and by year and application. Chevrolet, GMC, Buick, Cadillac and Pontiac vehicles also have their own brand archives on this site, so if you know which division your vehicle was sold under, it is worth checking that page as well.

What is stocked under GM

Transfer cases are the largest group and cover the MP1226, MP1626, MP3023 and MP3024 families used in Sierra and Silverado 2500/3500 trucks, along with NP231, NP233, NP236, NP246 and NP263HD units and BorgWarner BW1370/BW4401 units, in both manual-shift and electric-shift versions, with or without a shift motor. Manual transmissions include the NV4500 and the HM290. Differentials cover the GM 7.25, GM 8.25 and GM 9.25 axles.

Ordering the right unit

GM changed transfer case and axle specifications frequently, sometimes mid-year. Order with the VIN, the RPO code list from the glovebox label where you have it, and the tag number from the unit you are replacing. For a transfer case, confirm whether yours is manual shift or electric shift and whether a shift motor is included, because the listings state this explicitly and it is the most common source of a wrong order. For a differential, confirm the axle ratio and whether the unit is open or locking.

Warranty

A 6-month limited warranty applies as standard. On qualifying remanufactured units, a 7-year / 1,000,000-mile extended warranty and a core-fee waiver are available on request, so ask before you order. Variety Engines is an independent seller and is not affiliated with General Motors. Call 440-374-1039 with your VIN and tag number and we will confirm the unit before it ships.