Low/Reverse 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 low reverse/456 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 456 regulator valve through the CBR1/C456 FDBK circuit for gradual low reverse/456 clutch engagement. The low/reverse clutch is applied in PARK, REVERSE, NEUTRAL, 1st gear below 6 km/h (4 mph) and manual LOW position.
In REVERSE, both solenoid pressure from ON/OFF SSE and line pressure from the manual valve in the REVERSE circuit apply pressure to the clutch control bypass valve to position it for low/reverse clutch application. Regulated line pressure from the CBR1/C456 circuit is directed to the low/reverse clutch by the clutch control bypass valve through the CBR1 circuit to apply the low/reverse clutch.
When the low/reverse clutch is applied in PARK, NEUTRAL, LOW or 1st gear below 6 km/h (4 mph), only pressure from ON/OFF SSE , positions the clutch control bypass valve. Line pressure from the REVERSE circuit is not supplied by the manual valve.
When the low/reverse 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 low/reverse clutch. Solenoid pressure from SSE is removed from the clutch control bypass valve to position it to apply the O/D (4, 5, 6) clutch.
When the low/reverse 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 reverse/456 latch valve, low/reverse clutch and O/D (4, 5, 6) clutch to fill the unused circuits with unpressurized transmission fluid.
When the low/reverse clutch is released in 4th, 5th and 6th gears, 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 OFF position, the regulated pressure is directed to the O/D (4, 5, 6) clutch.