GM’s Hybrid Two-Mode 2MT70 Transmission, Part 1 - Transmission Digest

GM’s Hybrid Two-Mode 2MT70 Transmission, Part 1

As mentioned and promised in the February issue of Transmission Digest, we will take a quick peek at the front-wheel-drive version of the longitudinally mounted two-mode 2ML70 transmission, called the 2MT70 (Figure 1).

GM’s Hybrid Two-Mode 2MT70 Transmission, Part 1

Technically Speaking

Subject: Internal components
Unit: GM 2MT70
Vehicle Application: 2009 Saturn Vue 2.4-liter
Essential Reading: Rebuilder, Diagnostician
Author: Wayne Colonna, ATSG, Transmission Digest Technical Editor

Technically Speaking

  • Subject: Internal components
  • Unit: GM 2MT70
  • Vehicle Application: 2009 Saturn Vue 2.4-liter
  • Essential Reading: Rebuilder, Diagnostician
  • Author: Wayne Colonna, ATSG, Transmission Digest Technical Editor

As mentioned and promised in the February issue of Transmission Digest, we will take a quick peek at the front-wheel-drive version of the longitudinally mounted two-mode 2ML70 transmission, called the 2MT70 (Figure 1).

This transmission was used in the 2009 Saturn Vue 2.4-liter vehicle. By looking at the power-flow application chart in Figure 2, you can see how very close it is to the 2ML70 in its operation. For this reason, much of what was covered with the 2ML70 in the February, March and April issues of Transmission Digest will make for familiar viewing of this 2MT70.

The high-voltage wires for both motor/generators enter through the top of the transmission alongside the auxiliary-pump-harness and transmission internal-harness connectors (Figure 3).

With the side pan removed you can see the TCM and solenoid-body assembly (Figure 4).

The TCM assembly consists of four pressure switches, four clutch-pressure control solenoids (OE information says that PCS 6 is not used), a line-pressure control solenoid and a transmission-fluid-temperature sensor (Figure 5).

Once the TCM and valve-body assembly are removed there will be three accumulator assemblies and two checkballs in the case (Figure 6). The proper operation of these two checkballs is critical, as they are in both the lube and motor/generator cooling circuits.

Again, I thank the good folks at Alto for giving me the use of this transmission to make this article possible. It gives us the opportunity to see what may roll into your shop sooner than expected. Next month we will take a look at the inside of this unit.

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