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Automatic Transmission (Allison 1000)


Production Plant Location: White Marsh, Maryland

Production Years: 2001 to Current for Duramax

Approximate Weight: 330 Lbs

Max Input RPM: 5,000 RPM


2001 - 2005 : 5 speeds

2006 - Current: 6 speeds


Gear Ratios:

1st: 3.1

2nd: 1.81

3rd: 1.41

4th: 1

5th: 0.71

6th: 0.61*

R: 4.49

*6th gear only found in 2006-Current Allison equipped trucks.



1. External spin on filter that has reusable magenet on top that can be changed much like the engine oil filter.
2. Pan has drain plug for easy draining.
3. PTO optional in some 1-ton trucks.
4. 6 speed Allison at 60 MPH results in 1,550 RPM.
5. 5 speed Allison at 60 MPH results in 1,800 RPM.
6. Adjusts shift firmness and strategies according to driver style and power input. This is known as TAPS and can be reset using some
tuners or EFI Live.