The General Motors 9T45 (M3U) 9-speed automatic transmission has been produced since 2017 and is installed in popular models such as the GMC Terrain, Chevrolet Trailblazer, and Opel Astra. This automatic transmission is paired with the 1.5-liter LFV and LYX turbocharged engines, as well as the 1.5-liter LXD diesel.
Specifications
| Type | automatic transmission |
| Number of gears | 9 |
| Type of drive | front / all wheel |
| Engine volume, l | up to 1.5 |
| Torque output, Nm | up to 280 |
| Recommended oil | DEXRON VI |
| Oil capacity, liter | 9.0 |
| Partial replacement, liter | 5.7 |
| Maintenance | every 60 000 km |
| Gearbox lifespan, km | ~250 000 km |
| Weight, kg | 82 |
Gear ratios GM 9T45
Using the 2019 GMC Terrain with a 1.5-liter turbo engine as an example:
| Main | 3.47 |
| 1st | 4.689 |
| 2nd | 3.306 |
| 3rd | 3.012 |
| 4th | 2.446 |
| 5th | 1.923 |
| 6th | 1.446 |
| 7th | 1.000 |
| 8th | 0.747 |
| 9th | 0.617 |
| Reverse | 2.960 |
Using
The transmission was installed on:
- Buick Encore GX 1 (9BYB) in 2019 – …;
- Buick LaCrosse 3 (P2XX) in 2019 – …;
- Chevrolet Trailblazer 3 (9BYC) in 2020 – …;
- GMC Terrain 2 (D2XX) in 2017 – …;
- Opel Astra K (B16) in 2019 – 2021.
Disadvantages of the GM 9T45 gearbox
- In its early years, this automatic transmission presented many problems, but the main ones have already been fixed;
- The most common complaints were about software glitches, and firmware updates were released one after another;
- The first transmissions had a design defect that caused poor shifting when cold;
- It’s important to note that the solenoids are very sensitive to lubricant purity;
- However, the transmission deserves praise for its easy access to the valve body for cleaning and repair.
