Manual Transmission Description and Operation: Notes
WARNING: This page is about a different variant/trim than selected.
Manual transmissions are identified by the number of forward gears and the measured distance between the centerline of the output shaft and the counter gear.
The 6-speed manual transmission (RPO MM6/MZ6/MH3) incorporates the following features:
- An aluminum case
- Fully synchronized gearing with an enhanced synchronizer cone arrangement:
- Triple-cone: FIRST, SECOND
- Double-cone: THIRD, FOURTH, FIFTH, SIXTH, REVERSE
- An internal shift rail mechanism
- A remote transmission shift control mounted forward of the transmission
- An external transmission shift rod enabling the forward mount location of the transmission shift control
- An extended-length transmission output shaft mating directly to the rear axle drive pinion, in the rear of the differential housing
- Tapered roller bearings supporting the mainshaft and countershaft
- Caged roller bearings under all speed gears
- Solenoid inhibit of SECOND and THIRD gears
- Solenoid inhibit of REVERSE gear during predefined forward motion
These features combine to yield a rugged, reliable system capable of handling input torques of up to 637 N.m (470 lb ft) for the MM6, 583 N.m (430 lb ft) for the MZ6 and 813 N.m (600 lb ft) for the MH3.
The gear ratios are as follows:
| Gear | MM6 Ratio (:1) | MZ6 Ratio (:1) | MH3 Ratio (:1) |
|---|---|---|---|
| FIRST | 2.66 | 2.97 | 2.29 |
| SECOND | 1.78 | 2.07 | 1.61 |
| THIRD | 1.30 | 1.43 | 1.21 |
| FOURTH | 1.00 | 1.00 | 1.00 |
| FIFTH | 0.74 | 0.71 | 0.82 |
| SIXTH | 0.50 | 0.57 | 0.68 |
| REVERSE | 2.90 | 3.28 | 3.11 |