Allison 1000 Transmission

 

The Allison 1000 was built in 5 & 6 speed versions, the latter introduced in 2005. Though not without its weaknesses, the Allison is built on a strong foundation and a popular transmission amongst diesel truck owners.

Allison 1000 Gear Ratios:

1st	2nd	3rd	4th	5th	6th*	R
3.10	1.81	1.41	1.00	0.71	0.61	4.49

*6th gear is only found on 2006-present Allison 1000 transmissions. 2001-2005 Allison equipped trucks had 5-speeds.

Allison 1000 Specs:

Name:	Allison 1000
Production Plant:	White Marsh, Maryland
Applications:	- light/medium duty diesel trucks. - All Duramax diesel equipped Chevrolet/GMC trucks.
Production Years:	- First produced in 1999. - Produced for Duramax applications 2001 - present.
Speeds:	- 2001 - 2005 : 5 speeds - 2006 - present: 6 speeds
Weight:	330 lbs (w/ PTO option)
Max Input RPM:	5,000 RPM
ATF Requirements:	Dexron-III ATF

 

Allison 1000 Features:

• External filter eliminates need to change internal filter until overhaul is performed.
• PTO optoinal in 3500 GMC/Chevrolet trucks.
• 2 overdrive gears for better fuel economy. At 60 mph, the 6-speed Allison equipped truck cruises at 1,550 RPM (compared to the 5-speed versions 1,800 RPM engine speed at 60 mph)
• Adaptive learning technology links transmission to engine TCM. Users driver input to calculate & create ideal shift strategies.
• Limp mode locks transmission in 3rd gear if rapid or excess transmission occurs, allowing vehicle to safely brought to service station as soon as possible.
• Tow/Haul mode for enhanced trailer braking control.
• Cold operation mode that allows the engine to rev higher until the engine & transmission have reached ideal operating temperature.
• Torque converter locks for gears 3 - 6. Gears 1 & 2 operate in both locked & unlocked torque converter modes.
• Input Torque capacties:
  - 2001 to 2005 : 520 lb-ft
  - 2005 : 565 lb-ft
  - 2006 to 2007: 650 lb-ft
  - 2008 to 2009: 660 lb-ft
  - 2010 to present: 750 lb-ft

Allison 1000 Strengths & Weaknesses:

Strengths:	- Component strength; components robust size allows transmission to manage large quantities of torque. - Dual overdrive ratios allow for decreased operating RPM & increased fuel economy.
Weaknesses:	- Insufficient C3 clutch lubrication. The C3 clutch is only lubricated when it is engaged. Can lead to premature failure of this particular clutch. - C1 & C2 clutch pistons engage clutches from the side (off-center), causing uneven pressure & wear.