Manual Second - Second Gear may be selected at any time while the vehicle is being operated in a forward gear range. However, TCM control prevents the transmission from upshifting above Second gear. When the gear selector lever is moved to Manual Second from Manual Third - Third Gear, the manual valve also moves. Changes to the hydraulic and electrical systems are as follows:

Second Coast Clutch Applied

Manual Valve:: The volume of line pressure entering the 32 fluid circuit at the manual valve is increased to accommodate the added torque requirements for engine braking or increased engine load.

2-3 Shift Solenoid (SS) Valve:: The 2-3 SS valve is energised, allowing feed limit fluid to enter the 2-3 signal fluid circuit. 2-3 signal fluid overcomes 2-3 shift valve spring (372) force and moves the 2-3 shift valve (371) to the applied position. This allows 23 regulated fluid to enter the second coast clutch fluid circuit and also opens the overdrive clutch feed 1, intermediate clutch and 345 fluid circuits to exhaust.

3-4 Shift Control Valve:: 2-3 signal fluid is also routed to the 3-4 shift control valve (346) and moves the valve against 1-2 signal fluid pressure to keep the 3-4 shift valve (345) in the applied position.

Second Coast Clutch:: Second coast clutch fluid is directed to the second coast clutch piston to apply the second coast clutch plates.

Important: If the vehicle operating conditions are such that the TCM signals a Third, Fourth or Fifth gear state, the 2-3 solenoid will be de-energised. Thus a downshift will not occur until the vehicle speed is low enough not to overrev the engine - calibratable in the TCM.

Overdrive Clutch Releases

Overdrive Clutch Assembly:: Overdrive clutch fluid exhausts from the overdrive clutch piston, allowing the overdrive clutch plates to disengage.

#12 Ball Check Valve:: Overdrive clutch fluid seats the #12 ball check valve against the overdrive clutch feed 2 passage and enters the overdrive clutch feed 1 fluid circuit.

2-3 Shift Valve:: Exhausting overdrive clutch feed 2 fluid is routed through the 2-3 shift valve into the intermediate clutch fluid circuit.

Intermediate Clutch Releases

Intermediate Clutch Assembly:: Intermediate clutch fluid exhausts from the intermediate clutch piston, allowing the intermediate clutch plates to disengage.

2-3 Shift Valve:: Intermediate clutch fluid is routed through orifice #24 to the 2-3 shift valve where it exhausts.

Shift Accumulation

Intermediate Clutch Accumulator:: Intermediate clutch fluid also exhausts from the intermediate clutch accumulator assembly. Accumulator fluid moves the intermediate clutch accumulator piston against accumulator spring force in preparation for another application of the intermediate clutch.

If the converter clutch was applied when Manual Second was selected it will release during downshifting. Under normal operating conditions the converter clutch will not re-apply in Second gear.

Manual Second Gear