Overdrive Brake

OVERDRIVE BRAKE

Components

Overdrive Brake Disassembly
1. CHECK PISTON STROKE OF OVERDRIVE (O/D) BRAKE

a. Place the O/D case assembly onto the transmission case, facing the cutout portion of the O/D case to the down side of the transmission case.

HINT: Make sure that the oil hole of the O/D case is aligned with the oil hole of the transmission case.

b. Using a dial indicator, measure the O/D brake piston stroke while applying and releasing compressed air (392 - 785 kPa, 4 - 8 kgf/cm2 , 57 - 114 psi).

Piston stroke: 0.65 - 2.21 mm (0.0256 - 0.0870 inch)

If the values are non-standard, inspect the discs.
c. Remove the O/D case from the transmission case.

2. REMOVE FLANGE, DISCS, PLATES AND CUSHION PLATE
a. Using a screwdriver, remove the snap ring.
b. Remove the flange.

c. Remove the 3 discs and 3 plates.
d. Remove the cushion plate.
3. REMOVE O/D PLANETARY RING GEAR

a. Remove the O/D planetary ring gear.

b. Remove the bearing and 2 races.

4. REMOVE PISTON RETURN SPRINGS
a. Using a screwdriver, remove the snap ring.
b. Remove the spring seat and 12 springs.

5. REMOVE O/D BRAKE PISTON
a. Hold the O/D brake piston by hand, apply compressed air into the passage to remove the O/D brake piston.
b. Remove the 2 O-rings from the piston.

6. REMOVE OIL SEAL RINGS
Remove the 2 oil seal rings.

Overdrive Brake Inspection

INSPECT DISC, PLATE AND FLANGE
Check to see if the sliding surface of the disc, plate and flange are worn or burnt. If necessary, replace them.

HINT:
- If the lining of the disc is peeling off or discolored, or even if parts of the printed numbers are defaced, replace all discs.
- Before assembling new discs, soak them in Automatic Transmission Fluid (ATF) for at least 15 minutes.

Overdrive Brake Assembly

1. INSTALL OIL SEAL RINGS
a. Coat the 2 oil seal rings with ATF.
b. Install 2 oil seal rings to the O/D case, then snug them down by squeezing their ends together.

NOTICE: Do not spread the ring ends more than necessary.

HINT: After installing the oil seal rings, check that they rotate smoothly.

2. INSTALL OVERDRIVE BRAKE PISTON
a. Coat 2 new O-rings with ATF and install them on the O/D brake piston.
b. Being careful not to damage the O-rings, press in the brake piston into the O/D case with both hands.
3. INSTALL PISTON RETURN SPRINGS

a. Install the 12 piston return springs, as shown.

b. Install the spring seat.
c. Pushing the spring seat, install the snap ring. Be sure the end gap of the snap ring is not aligned with the cutout portion of the O/D case.

HINT: Make sure that the snap ring is inserted in its groove.

4. INSTALL O/D PLANETARY RING GEAR
a. Coat the bearing and races with petroleum jelly and install them onto the O/D case.

Bearing and races diameter

b. Install the O/D planetary ring gear.

5. INSTALL CUSHION PLATE

6. INSTALL PLATES AND DISCS
Install the 3 plates and 3 discs.
Install in order: P=Plate D=Disc
P - D - P - D - P - D

7. INSTALL FLANGE
a. Install the flange, the rounded edge facing upward.
b. Using a screwdriver, install the snap ring. Be sure the end gap of the snap ring is not aligned with the cutout portion of the O/D case.
8. CHECK PISTON STROKE OF OVERDRIVE BRAKE

b. Using a dial indicator, measure the O/D brake piston stroke while applying and releasing compressed air (392 - 785 kPa, 4 - 8 kgf/cm2 , 57 - 114 psi).

Piston stroke: 0.65 - 2.21 mm (0.0256 - 0.0870 inch)

If the piston stroke is less than the limit, parts may have been assembled incorrectly, check and reassemble again.