GM 6-Speed 6L45 MYA Hydra-Matic Automatic Transmission
The Hydra-Matic 6L45 (production code MYA) is a six-speed automatic transmission produced by General Motors for use in rear- and rear-biased all-wheel-drive vehicles with a longitudinal powertrain orientation. Developed in-house by General Motors, the Hydra-Matic 6L45 is part of the 6LXX family of fuel-saving, electronically controlled six-speed automatic transmissions that succeeded the 5LXX family.
The modular design of the Hydra-Matic 6L45 (MYA) is shared with variants rated for different torque levels to accommodate various engines and vehicle applications. All versions share a unique output gearset configuration that enables it a wider range of ratios than a conventional planetary gearset automatic transmission. This allows the transmission to be tailored for optimal fuel economy while delivering excellent acceleration traits.
The wide overall ratio spread of 6.04:1 allows a “steep” first gear, as well as a very “tall” overdrive top gear for low-rpm highway cruising.
The modular concept of the Hydra-Matic 6L45 centers on the desire for common components and manufacturing tooling for four different size variants of the six-speed family. All versions use three gearsets: a simple input planetary gearset and two output gearsets, one of which is a compound gearset with three pairs of two pinion gears on the output carrier, one pair meshing with the sun gear and the other with the ring gear.
Performance Algorithm Braking
Performance Algorithm Shifting is available on some applications. Performance Algorithm Shifting (PAS) monitors how assertively the driver is using engine output to determine at what engine speed to upshift or downshift.
Driver Shift Control
Driver Shift Control allows the driver to shift the transmission like a clutchless manual gearbox. Electronic safeguards prevent over-revving should the wrong gear position be accidentally selected.
Advanced Control System
Advances in transmission control modules allow them to exist reliably inside the transmission, where temperatures remain fairly constant compared to a body-mounted module. The transmission and module are assembled together, so no additional steps are necessary during vehicle assembly.
The 6L45’s 32-bit transmission control module (TCM) monitors transmission performance and compensates for normal wear in components such as clutch plates, so transmission performance remains consistent for the life of the transmission.
|Type:||Six speed RWD / AWD, electronically controlled automatic overdrive transmission with torque converter clutch. Clutch-to-clutch architecture, with integral Electro / Hydraulic Controls Module|
|Maximum engine power:||321 bhp (239 kw)|
|Maximum engine torque:||275 lb-ft (373 Nm)|
|Maximum gearbox torque:||405 lb-ft (550 Nm)|
|Maximum shift speed:||7000 rpm|
|Maximum Validated Weight (GVW):||5620 lb (2549 kg)|
|Maximum Validated Weight (GCVW):||9300 lb (4251 kg)|
|7-position quadrant:||P, R, N, D, X, X, X (X = available calibratable range position)|
|Case description (OEM):||2-piece (Bell, main case)|
|Case description (GM):||Bell + case + extension|
|Case material:||Die cast aluminum|
|Shift pattern:||(2) Three-way on/off solenoids|
|Shift quality:||Five variable bleed solenoid|
|Torque converter clutch:||Variable Bleed Solenoid ECCC|
|Converter size:||230 mm,240 mm,258 mm|
|Fluid type:||DEXRON VI|
|Fluid capacity with 258 & 300 mm converter:||7.30 kg|
|Transmission weight (wet with 258 & 300 mm converter):||77.75-78.16 kg (171-172 lb) estimated|
|Pressure taps available:||Line pressure|
|Assembly site:||GMPT Strasbourg, France|
|Available Control Features|
|Multiple Shift Patterns (Selectable)|
|Driver Shift Control (Tap Up / Tap Down)|
|Enhanced Performance Algorithm Shifting (PAS)|
|Selectable Tow / Haul Mode|
|Engine Torque Management On All Shifts|
|Altitude and Temperature Compensation|
|Adaptive Shift Time|
|Automatic Grade Braking|
|OBDII / EOBD|
|Integral Electro/Hydraulic Controls Module (Tehcm)|
|Control Interface Protocol – GMLAN|
|Cadillac ATS Sedan||2.5L I4 LCV NA|
|Cadillac ATS Sedan and Coupe||2.0L I4 LTG Turbo|
|Cadillac ATS Sedan and Coupe||3.6L V6 LFX NA|
|Cadillac CTS Sedan||2.0L I4 LTG Turbo|
|Chevrolet Caprice PPV||3.6L V6 LFX NA|