GM Service Manual Online
For 1990-2009 cars only

When the gear selector lever is moved to the Reverse (R) position (from the Park position) the normally-high 35R pressure control solenoid 2 is commanded ON and the following changes occur in the transmission’s hydraulic and electrical systems:

3-5-Reverse Clutch Applies

Manual Valve

With the manual valve in the reverse position, line pressure is directed into the reverse fluid circuit and routed to the clutch select valve.

Clutch Select Valve

Reverse fluid is routed to a differential area of the default override shuttle valve and assists shift solenoid fluid, present at the valve from Park position, in holding the clutch select valve against clutch select valve spring force. Reverse fluid passes through the clutch select valve into the 35 reverse clutch feed circuit and is routed to the #2 ball check valve. R1/456 clutch feed fluid, present at the valve from Park position, continues to pass through the valve into the R1 circuit in order to keep the low and reverse clutch applied.

#2 Ball Check Valve

3-5 reverse fluid passes through orifice #5, seats the #2 ball check valve against the drive 1-6 fluid passage, and enters the 35 reverse/drive 1-6 circuit. 35 reverse/drive 1-6 fluid is routed through orifice #25 to the 3-5-reverse clutch regulator valve.

35R Pressure Control (PC) Solenoid 2

The 35R PC solenoid 2 is energized (ON), allowing actuator feed limit fluid to enter the PCS 35 reverse clutch circuit. PCS 35 reverse clutch fluid is then routed through orifice #26 to the 3-5-reverse clutch regulator valve.

3-5-Reverse Clutch Regulator Valve

PCS 35 reverse clutch fluid, at the 3-5-reverse clutch regulator valve, opposes 3-5-reverse clutch regulator valve spring force and orificed 35 reverse clutch feedback fluid pressure to regulate 35 reverse clutch feed/drive 1-6 pressure into the 35 reverse clutch circuit. 35 reverse clutch fluid is then routed to the 3-5-reverse clutch, and through orifice #33 to the #6 ball check valve.

3-5-Reverse Clutch

35 reverse clutch fluid enters the 3-5-reverse and 4-5-6 clutch housing assembly to move the 3-5 reverse clutch piston against spring force and compensator feed fluid pressure to apply the 3-5-reverse clutch plates.

#6 Ball Check Valve

35 reverse clutch feed fluid unseats the #6 ball check valve, allowing excess pressure to pass into the actuator feed limit circuit. This helps to control clutch apply fluid pressure and clutch apply feel.

Reverse


Object Number: 1912890  Size: FS