Functional Inspection 3

Functional Inspection 3 is a mechanical system inspection for both the left and right side gerotor pumps, pistons, and clutch packs and will assist in determining if:

• The clutch pump check valve is in the "open" position.
• The left and right side gerotor pumps have the ability to "pull" fluid from the sump and send a variable and progressive rate of pressurized fluid to the left and right side clutch pack pistons.
• The left and right side pistons will engage the specific side clutch packs at a progressive rate.
• The rear differential has the ability to provide rear wheel torque and override the resistance created by the parking brake assembly.
• There is a mechanical connection between the rear differential ring and pinion, the propeller shaft, the transfer case, and the transmission assembly.

1. Raise the vehicle on a hoist. Lift the vehicle in a manner that will allow all four wheels to rotate during testing.
2. Start the engine.
3. Move the gear shift lever to the DRIVE position.
4. Accelerate the vehicle lightly until all four wheels are rotating at an equal slow speed.
5. Depress the parking brake slightly, gradually increasing the parking brake retention to create resistance in the rear wheels. The rear wheels should stop spinning. The front wheels should remain spinning.
IMPORTANT: Do not accelerate the vehicle with the parking brake applied for a period longer than 5-7 seconds.
6. Lightly depress the accelerator pedal, increasing engine rpms in order to determine if the rear wheels can provide enough torque to "override" the resistance created by the parking brake assembly. Failure of the rear wheels to rotate during this test may indicate a "closed" clutch pump check valve, malfunctioning gerotor pump, piston, clutch pack, or valves internal to the unit.