Front Section Power Flow

Note: The heavy lines in the image below outline the power flow description below.

• Power (torque) from the engine is transferred to the transmission’s Input Shaft.
• The Input Shaft rotates the Main Drive Gear through internal splines in the hub of the gear.
• The Main Drive Gear meshes with both Counter Shaft driven gears, and the torque is split between both Counter Shafts.
• Because the Counter Shaft gears are in constant mesh with the Main Shaft gears, all the front section gearing rotates. However, only the engaged Main Shaft gear will have torque. External clutching teeth on the sliding clutch will engage internal clutching teeth on the selected Main Shaft gear. Torque will now be provided from both opposing Counter Shaft gears, into the engaged Main Shaft gear, and through the sliding clutch to the front section Main Shaft.
• The rear of the front section Main Shaft is splined into the Auxiliary Drive Gear, and torque is now delivered to the Auxiliary Section.

Front Section Torque (1st Gear)

Front Section Power Flow - Direct Gear

In direct gear (5th/10th for FA model, 4th/9th for FAO model), the front sliding clutch is moved forward and engages into the back of the Main Drive Gear. Torque will flow from the Input Shaft to the Main Drive Gear, Main Drive Gear to sliding clutch, sliding clutch straight into the front section Main Shaft which delivers the torque to the Auxiliary Drive Gear.

Note: All Counter Shaft and Main Shaft gears will rotate, but not all gears will be loaded.

5th Gear FM, 4th Gear FO & FOM

10th Gear FM, 9th Gear FO & FOM

Front Section Power Flow - Reverse Gear

Torque will flow from the Counter Shafts to the Reverse Idler gears. Torque will then flow from the Reverse Idler gears to the Main Shaft Reverse Gear. Torque will now travel through the Main Shaft Reverse Gear, the sliding clutch in the Reverse position and then to the Main Shaft and Auxiliary Drive Gear

Reverse Gear—Low Range

Auxiliary Section Power Flow - Low Range

The Auxiliary Drive Gear transfers torque to both Auxiliary Counter Shafts.

If the Auxiliary Section is in low range, the Range Sliding Clutch is rearward and engaged into the Auxiliary Main Shaft Reduction Gear, through the Range Sliding Clutch and then into the Output Shaft (Auxiliary Main Shaft).

Low Range (Auxiliary Sliding Clutch Back)

Auxiliary Section Power Flow - High Range

If the Auxiliary Section is in high range, the Range Sliding Clutch is forward and engaged into the back of the Auxiliary Drive Gear. Torque will flow from the Auxiliary Drive Gear to the Range Sliding Clutch. Because the Range Sliding Clutch has internal splines which connect to the Output Shaft, torque will flow straight through the Auxiliary Section.

High Range (Auxiliary Sliding Clutch Forward)

FM/FO/FOM

1st Gear

2nd Gear

3rd Gear

4th Gear—FM/Direct Drive Transmission 5th Gear—FO & FOM/Overdrive Transmission

5th Gear—FM/Direct Drive Transmission 4th Gear—FO & FOM/Overdrive Transmission

6th Gear

7th Gear

8th Gear

9th Gear—FM/Direct Drive Transmission 10th Gear—FO & FOM/Overdrive Transmission

10th Gear—FM/Direct Drive Transmission 9th Gear—FO & FOM/Overdrive Transmission