Transmission General Description
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Allison 1000 Series transmissions are torque converter driven, fully automatic, transmission systems. The 1000 Series transmissions have 6 forward speeds, NEUTRAL, and REVERSE. The fifth and sixth range has overdrive gear ratio. The 1000 Series incorporates a variety of standard and optional design features. These design features include the following:
- Direct mount to engine block
- Flexplate drive
- Torque converter with a torque converter clutch (TCC) and integral vibration damper
- 3 constant-mesh planetary gear sets with helical gears
- 5 multiple disk clutches - 2 rotating and 3 stationary
- Common hydraulic system for all transmission functions
- 2 transmission fluid filtration systems
- Electrohydraulic control valve assembly
- Electronically controlled automatic gear selection and clutch apply
- Fill tube/dipstick provision on both sides of transmission
- Parking pawl
- Power takeoff (PTO) provision on both sides of transmission