An Allison 1000 automatic, with the Allison name cast into the case and photographed close up. The unit is complete with its bellhousing, pan, external lines and a rear output yoke, and sits strapped to a rolling dolly. It is dirty and weathered: heavy oil residue and grime over the case, old gasket material around the pan rail, and white corrosion on the aluminium. The bellhousing photograph shows the input shaft and pump exposed, so no torque converter is fitted, and we have not opened or tested it.
A further housing with its own yoke is bolted to the tail in the third photograph, so tell us your year, cab and bed length and we will confirm exactly what is included and that it fits before you order.
Allison 1000: fitment and related parts
- Every part we hold for GMC
- The rest of our drivetrain
- Not sure of your trim? Decode your VIN with the NHTSA VIN decoder, then send it to us and we confirm fit before you pay











