Forward and Overrun Clutches

Forward and Overrun Clutches




Service procedures for forward and overrun clutches are essentially the same as those for reverse clutch, with the following exception:
- Check of forward clutch operation.




- Check of overrun clutch operation.




- Removal of forward clutch drum
Remove forward clutch drum from transmission case by holding snap ring.




- Removal of forward clutch and overrun clutch pistons

1. While holding overrun clutch piston, gradually apply compressed air to oil hole.




2. Remove overrun clutch from forward clutch.




- Removal and installation of return springs

Inspection Standard:

- inspection of forward clutch and overrun clutch return springs




- inspection of forward clutch drive plates

Thickness of drive plate:
Standard 2.0 mm (0.079 in)
Wear limit 1.8 mm (0.071 in)




- Inspection of overrun clutch drive plates

Thickness of drive plate:
Standard 2.0 mm (0.079 in)
Wear limit 1.8 mm (0.071 in)




- Installation of forward clutch piston and overrun clutch piston
1. install forward clutch piston by turning it slowly and evenly.
- Apply A.T.F. to inner surface of clutch drum.




- Align notch in forward clutch piston with groove in forward clutch drum.




2. Install overrun clutch by turning it slowly and evenly.
- Apply A.T.F. to inner surface of forward clutch piston.




- Measurement of clearance between retaining plate and snap ring of overrun clutch

Specified clearance:
Standard 1.0 - 1.4 mm (0.039 - 0.055 in)
Allowable limit 2.0 mm (0.079 in)

Retaining plate: Refer to S.D.S.




- Measurement of clearance between retaining plate and snap ring of forward clutch

Specified clearance:
Standard 0.45 - 0.85 mm (0.0177 - 0.0335 in)
Allowable limit 1.85 mm (0.0728 in)

Retaining plate: Refer to S.D.S.