Allison 1000 transmission

All are 5 or 6-speed electronically controlled units and are manufactured by Allison Transmission in Indianapolis, Indiana as well as in Baltimore, Maryland and in Erskine, Minnesota.

There are 3 consecutive planetary systems and the planet carrier of a stage is permanently connected to the ring gear of the following stage, except for the last system where the carrier is connected to the output shaft.

For those, ring 3 is connected to the input and additional speed is added by rotation of sun 3.

This rating has increased as the transmission was updated several times, to stand at 765 lb⋅ft (1,037 N⋅m) by 2011 in GM truck applications.

[2] 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.

This feature gives the driver greater control over the transmission, enhancing operation when engine braking or less frequent shifting is desired.