The 1000 series (and similar 2000 and 2400 series) is a line of automatic transmissions for on-road trucks. All are 5 or 6-speed electronically controlled units and are manufactured by General Motors' Allison Transmission division in Indianapolis, Indiana as well as in Baltimore, Maryland.
The Allison 1000 is rated to handle up to 620 lb·ft (841 N·m) of torque. Initially it was a 5 speed transmission, but a new "Generation 4" 1000 was introduced in 2005 that added a 6th gear at the very top of the ratio ladder, making it a double-overdrive like heavier duty Allison transmissions. For the 2006 model year, manual gear selection was introduced. This feature gives the driver greater control over the transmission, enhancing operation when engine braking or less frequent shifting is desired.
Gear ratios:
| 1 | 2 | 3 | 4 | 5 | 6 | R |
|---|---|---|---|---|---|---|
| 3.10 | 1.81 | 1.41 | 1.00 | 0.71 | 0.61 (06+) | 4.49 |
Applications:
The Allison 2000 is rated to handle up to 620 lb·ft (841 N·m) of torque.
Gear ratios:
| 1 | 2 | 3 | 4 | 5 | R |
|---|---|---|---|---|---|
| 3.51 | 1.90 | 1.44 | 1.00 | 0.74 | 5.09 |
Applications: