Manual Transmission
Manual Transmission
The M5OD-R1 is a 5-speed manual transmission equipped with the following features:
- An aluminum main case, extension housing and shift control housing.
- A countershaft that is serviced as an assembly.
- Helical cut gears, including reverse.
- Shift rails that are mounted on the shift cover. Detents are used to hold the shift forks in their selected positions. Interlocks prevent engagement of more than one gear at a time.
- Gear changes that are accomplished with synchronizer sleeves.
- Full synchronization in all gears.
- A unique extension housing and output shaft for Four-Wheel Drive (4WD) vehicles.
The function of the transmission is to move the vehicle from a rest position to motion. This is done by transferring the engine torque to the vehicle's rear wheels. This power (torque) is delivered from the engine flywheel to the transmission. It is transmitted through a driver-operated clutch, which allows for engagement and disengagement of the engine to the transmission.
The transmission input shaft receives the power when the clutch is engaged. It is transferred through the input shaft to the drive gear. Torque is transferred to the countershaft drive gear and is delivered along the countershaft to all the countershaft gears. Torque is then transferred to the engaged mainshaft gear.
The transmission then uses a system of gears to change the speed and torque relationship between the engine crankshaft and the transmission output shaft.
Transmission Identification
The Vehicle Safety Compliance Label (located on the driver door lock pillar) lists applicable transmission identification codes. For information on codes, refer to Identification Codes Application and ID.
Manual transmissions are also equipped with service identification tags. The M5OD-R1 tag is located on the driver side of the transmission.
Lubrication
The M5OD-R1 transmissions are designed so that the internal parts operate in an oil bath circulated by the motion of the gears and shafts. All parts are amply lubricated if these procedures are followed:
- Maintain the correct fluid level by inspecting it regularly.
- Change the fluid at recommended intervals. Refer to the Owner's Literature for the recommended intervals.
High operating temperatures increase the lubricant's rate of oxidation and shorten its effective life. When the average operating temperature is high, the transmission may require more frequent fluid changes. The following conditions in any combination can cause high operating temperatures:
- Operating consistently at slow speeds
- High ambient temperatures
- Restricted air flow around the transmission
- Exhaust system too close to the transmission
Powerflow in Neutral
- The input gear drives the countershaft.
- The countershaft gears drive the 1st, 2nd and 3rd gears on the output shaft.
- All the synchronizers are disengaged (centered).
- No gears are engaged to the output shaft.
- The output shaft is not engaged to the input shaft.
Powerflow in 1st Gear
- The input gear drives the countershaft.
- The countershaft gears drive the 1st, 2nd, 3rd and 5th gears on the output shaft.
- The 1-2 synchronizer hub is splined to the output shaft.
- When the synchronizer sleeve is shifted rearward, 1st gear is locked to the output shaft.
Powerflow in 2nd Gear
- The input gear drives the countershaft.
- The countershaft gears drive the 1st, 2nd, 3rd and 5th gears on the output shaft.
- The 1-2 synchronizer hub is splined to the output shaft.
- When the synchronizer sleeve is shifted forward, 2nd gear is locked to the output shaft.
Powerflow in 3rd Gear
- The input gear drives the countershaft.
- The countershaft gears drive the 1st, 2nd, 3rd and 5th gears on the output shaft.
- The 3-4 synchronizer hub is splined to the output shaft.
- When the synchronizer sleeve is shifted rearward, 3rd gear is locked to the output shaft.
Powerflow in 4th Gear
- The input gear drives the countershaft.
- The countershaft gears drive the 1st, 2nd, 3rd and 5th gears on the output shaft.
- The 3-4 synchronizer hub is splined to the output shaft, but no gears are engaged to the output shaft.
- When the synchronizer sleeve is shifted forward, the input shaft is locked to the output shaft through the synchronizer hub.
Powerflow in 5th Gear
- The input gear drives the countershaft.
- The countershaft gears drive the 1st, 2nd and 3rd gears on the output shaft, and the 5th gear synchronizer.
- The 5th gear synchronizer hub is splined to the countershaft.
- When the synchronizer sleeve is shifted forward, the 5th gear is locked to the countershaft.
- The countershaft 5th gear drives the output shaft 5th gear.
Powerflow in Reverse Gear
- The input gear drives the countershaft.
- The 5th-reverse synchronizer hub is splined to the countershaft.
- The synchronizer hub engages the reverse gear to the countershaft.
- The countershaft reverse gear drives the reverse idler gear.
- The reverse idler gear drives the reverse gear on the countershaft, in a REVERSE direction.