Overdrive (4, 5, 6) Clutch Hydraulic Circuits
Line pressure is supplied to the low reverse/456 regulator valve by the pump in every gear and manual lever position. To apply the low/reverse clutch, SSD supplies varying solenoid pressure to the low reverse/456 regulator and latch valves. As the regulator valve moves, it supplies the clutch control bypass valve and low reverse/456 latch valve with regulated line pressure through the CBR1/C456 circuit. The low reverse/456 latch valve directs the regulated line pressure to the opposite side of the low reverse/456 regulator valve through the CBR1/C456 FDBK circuit for gradual O/D (4, 5, 6) clutch engagement.
To apply the O/D (4, 5, 6) clutch, the position of the clutch control bypass valve allows the regulated line pressure in the CBR1/C456 circuit to supply the C456 circuit, applying the O/D (4, 5, 6) clutch. Clutch control bypass valve latch pressure is supplied by the C456 circuit. The O/D (4, 5, 6) clutch is applied in 4th, 5th and 6th gears.
When the O/D (4, 5, 6) clutch is released in 1st gear above 6 km/h (4 mph), 2nd and 3rd gears, solenoid pressure from SSD is removed from the low reverse/456 regulator and latch valves which positions the valves to block line pressure and release the O/D (4, 5, 6) clutch.
When the O/D (4, 5, 6) clutch is released in 1st gear above 6 km/h (4 mph), 2nd and 3rd gears, exhaust backfill supplied to the low reverse/456 clutch regulator valve and the clutch control bypass valve by the manual valve through the EXH BF circuit is directed to the low reverses latch valve, low/reverse clutch and O/D (4, 5, 6) clutch to fill the unused circuits with unpressurized transmission fluid.
When the O/D (4, 5, 6) clutch is released in PARK, REVERSE, NEUTRAL and 1st gear below 6 km/h (4 mph), the low reverse/456 regulator valve supplies regulated pressure to the clutch control bypass valve through the CBR1/C456 circuit. With ON/OFF SSE in the ON position, the regulated pressure is directed to the low/reverse clutch.