Slips in Reverse or No Reverse. Chevrolet Epica 2008

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2008 🢒 Epica 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - Aisin 55-51LE 🢒 Slips in Reverse or No Reverse

Slips in Reverse or No Reverse

Condition

Action

DEFINITION: Slips in reverse or no reverse

Fluid Level Low and/or Contaminated or unit filled with the wrong type of fluid

Inspect fluid level and color. Perform a fluid level inspection and make sure that the fluid does not smell burnt, and shows no sign of coolant cross contamination. If unable to determine if the transmission has the correct type of fluid, drain the unit and refill with the correct fluid and retest.

Torque Converter (1)

Internal concern, diagnose the cause of the concern and correct as necessary. Replace the torque converter assembly.

Low System Line Pressure

Fluid

Low fluid level, perform fluid level check and correct as needed.

Fluid Pump (2)

Internal fluid pump (2) concern, diagnose fluid pump assembly and repair or replace assembly as necessary.

Torque Converter (1)

Internal concern, diagnose the cause of the concern and repair as necessary. Replace the torque converter assembly.

Fluid Filter (42)

Fluid filter (42) restricted. Diagnose the cause of the restriction and repair as necessary and replace the filter assembly.

Internal Transmission Concerns

Internal fluid leak, perform system air checks and repair as necessary.

External Control Valve Body Assembly (39)

•	Line Pressure Control Solenoid Valve Assembly (SLT) (316)

•	Reverse, 1st Shift Solenoid Valve Assembly (S1) (310)

•	2-3, 3-4 Shift Solenoid Valve Assembly (S2) (308)

Verify that all solenoids respond electrically. If there is no response, perform an electrical diagnosis. If there are no electrical concerns, remove the solenoid valve assembly as needed, and inspect the solenoids O-ring seals, and bores for signs of damage and/or missing seals. If the valves responded electrically and there are no bore or seal concerns, replace assembly as required due to a possible internal mechanical concern and retest. If after replacing the valve assembly in question, a concern is still present, replace the complete control valve body assembly (39).

Internal Control Valve Body Assembly (39)

•	Primary Regulator Valve (395)

•	Check Valve (360)

•	Manual Valve (337)

•	M1 Shift Valve (389)

•	M2 Shift Valve (426)

•	U1 Shift Valve (386)

•	Line Pressure Control (SLT) Accumulator Piston (433)

•	Remove the control valve body assembly to inspect the items listed.

•	Inspect internal bores and valves for signs of wear and/or damage, including internal contamination.

If unable to verify a repairable concern, replace the complete valve body assembly.

Clutch - Mechanical/Hydraulic

Forward (C1) Clutch

Remove the transmission case cover and 1-2 reverse clutch assembly (B5) (19) and the forward and direct clutch assembly (23). Inspect all forward clutch (C1) components and operation. Repair as necessary.

Low and Reverse Clutch Piston Assembly (27)

Remove the transmission case cover and 1-2 reverse clutch assembly (B5) (19), the forward and direct clutch assembly (23), the front internal gear and low clutch sprag (F2) assembly (25), and the low and reverse clutch plates and disc assembly (B3) (26). Inspect the low and reverse clutch piston (27) and related components for proper operation. Repair as necessary.

1-2 Reverse (B5) Clutch Assembly

Remove the transmission case cover and 1-2 reverse clutch assembly (B5) (19). Inspect all 1-2 reverse (B5) clutch components and operation. Repair as necessary.