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Allison 1000 Transmission

Allison 1000 Transmission Specs & Gear Ratios

 

 

 

The Allison 1000 was first produced in 1999 by Allison Transmission. In 2001, GM mated the Allison to its new 6.6L Duramax. The Allison 1000 is arguably one of the most desirable automatic transmissions on the market. Its popularity and excellent reputation can be attributed to its strength, reliability, and the technology applied to the transmission. In 2006, the Allison 1000 was converted from a 5 speed to a 6 speed automatic, making the later version a double overdrive. Not without flaws, the Allison suffers from lack of lubrication to the C3 clutch, while the C1 & C2 clutches are applied off center, causing uneven wear and premature failure. The transmission is also known to lock into limp mode when owners begin adding performance enhancers to their Duramax. Performance products, like programmers, push the Duramax beyond the transmission's limits and can cause excessive slippage, forcing the transmission to lock into 3rd gear. Regardless, the Allison is a heavy duty transmission with much to be desired. The aftermarket has many products available for building bulletproof Allison 1000s, making it a popular transmission in sled pulling and other diesel motorsports.

 

Allison 1000 6 Speed Ratios

Gear:

1

2

3

4

5

6

R

Ratio:

3.10 : 1

1.81 : 1

1.41 : 1

1.00 : 1

0.71 : 1

0.61 : 1

4.49 : 1

(2006 to present model years)

 

Allison 1000 5 Speed Ratios

Gear:

1

2

3

4

5

R

Ratio:

3.10 : 1

1.81 : 1

1.41 : 1

1.00 : 1

0.71 : 1

4.49 : 1

(2001 - 2005 model years)

 

Allison 1000 Transmission Specs

Transmission:

Allison 1000 5/6 Speed automatic transmission

Manufacturer:

Allison Transmission

Production Run:

2001 - present

ATF:

• Dexron III (recommended by GM)

• TranSynd full synthetic Dexron III (recommended by Allison)

Transmission Weight:

Approx. 330 lbs

Features:

• Double overdrive (2006+).
• Optional PTO provisions.
• Maximum 5,000 rpm input rating.
• 26,000 maximum GCW.
• Adaptive Learning Technology; transmission constantly measures drive parameters and optimizes shifts accordingly.
• Electronic transmission controls integrated with Duramax diesel to provide optimum shift schedules.
Limp Mode: occurs when excessive slippage is sensed or transmission loses communication with engine. Locks trans in 3rd gear.

 

Allison 1000 Max Input Torque

Year

Max. Input Torque

2001 - 2004

520 lb-ft

2005

565 lb-ft

2006 - 2007

650 lb-ft

2008 - 2009

660 lb-ft

2010 +

Est. 775 lb-ft +