When testing the pressure of a specific clutch, it is necessary to isolate the clutch being tested. For example, on a 6-speed transmission, to check the Forward Low (T) clutch, one must select 2nd gear—an action that engages both the Forward Low (T) and Intermediate Shaft (Z) clutches. Since the objective is to check the pressure of the Forward Low (T) clutch alone—excluding the Intermediate Shaft (Z) clutch—the electrical connector for the 6-speed transmission’s Zs solenoid must be disconnected prior to selecting 2nd gear.

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Refer to the table below to determine which solenoid electrical connectors should be disconnected when performing pressure tests on individual clutches. Note that because the first three forward gears and the reverse gear utilize all the clutches, no specific gear selection is required when testing for leaks in those instances. 6-Speed ​​Gearbox

Gear / Clutches Engaged (Solenoids Energised) / Selected 1st Forward: Forward Low & Layshaft – X, Z (Xs, Zs) 2nd Forward: Forward Low & Layshaft – T, Z (Ts, Zs) 3rd Forward: Forward High & Layshaft – U, Z (Us, Zs) 1st Reverse: Reverse Low & Layshaft – W, Z (Ws, Zs) 2nd Reverse: Reverse High & Layshaft – V, Z (Vs, Zs) 3rd Reverse: Reverse Low & Mainshaft – W, Y (Ws, Ys) 4-Speed ​​Gearbox

Gear / Clutches Engaged (Solenoids Energised) / Selected 1st Forward: Forward Low & Layshaft – T, Z (Ts, Zs) 2nd Forward: Forward High & Layshaft – U, Z (Us, Zs) 3rd Forward: Forward Low & Mainshaft – T, Y (Ts, Ys) 1st Reverse: Reverse Low & Layshaft – W, Z (Ws, Zs) 2nd Reverse: Reverse High & Layshaft – V, Z (Vs, Zs) 3rd Reverse: Reverse Low & Mainshaft – W, Y (Ws, Ys) In the following procedure, the Forward Low clutch (T) is being tested; therefore, in step 2,

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connect the pressure gauge to the Forward Low clutch test point.

When testing other suspected clutches, connect the gauge to the relevant test point

for the clutch in question. Since there is an issue with the Forward Low clutch,

a gear that utilizes the Forward Low clutch must be selected—in this case, 2nd Forward gear.

Note: When testing the 2/4-wheel drive clutch, remove oil supply pipe R and install the service tool.

This pipe contains a test point. Replace the original pipe after testing is complete. 1 Stop the engine and connect a 0–20 bar (0–300 lbf/in²) pressure gauge to test connection A (main line pressure test point).

2 Connect a 0–20 bar (0–300 lbf/in²) pressure gauge to test connection T (forward low-speed clutch test point).

3 Disconnect the supply connector Zs for the countershaft clutch solenoid valve at the solenoid control valve assembly. This ensures that only the forward low-speed clutch T is energized when Forward 2nd gear is selected.

4 Ensure all four wheels are chocked on both sides. Depress the service brake and apply the parking brake. Note: When fully applied, the parking brake electronically disengages the transmission drive; this prevents the machine from moving while the parking brake is engaged. Therefore, to complete the test, move the parking brake lever slightly forward until the warning light just goes out; hold the lever in this position during the test. Do not move the lever too far forward, or the parking brake will not function fully. Alternatively, the parking brake switch can be disconnected.

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Start the engine, run it at 1000 rpm, and select Forward 2nd gear. Observe the pressure readings on both gauges; the difference between the readings should not exceed 0.7 bar (10 psi). If the difference between the gauges exceeds 0.7 bar (10 psi), perform the following:

Stop the engine and swap the gauges.

Start the engine, run it at 1000 rpm, and select Forward 2nd gear.

If the difference between the gauges remains greater than 0.7 bar (10 lbf/in²), remove the forward low-speed clutch for repair. c If the reading differs from that in step 5 after swapping the measuring instruments, calibrate the instrument and repeat the test procedure.