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Overdrive Unit
± AUTOMATIC TRANSAXLEComponent Parts (Overdrive Unit) (A540E and A540H)AT±290
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INSPECTION OF OVERDRIVE BRAKE
INSPECT DISCS, PLATES AND FLANGE
Check if the sliding surfaces of the discs, plates and
flange are worn or burnt. If necessary, replace them.
HINT:
wIf the lining of the disc is exfoliated or discolored, or
even a part of the printed numbers are defaced, re-
place all discs.
wBefore assembling new discs, soak them in ATF for
at least fifteen minutes.
DISASSEMBLY OF OVERDRIVE
BRAKE
1. REMOVE PISTON RETURN SPRING
(a) While pushing the return spring, remove the snap
ring with a screwdriver.
(b) Remove the piston return spring.
3. REMOVE PISTON FROM DRUM
Apply compressed air to oil hole to remove the piston.
HINT: Blow with the gun slightly away from the oil hole,
and be careful that the piston dose not tilt.
4. REMOVE 4±RINGS
Remove the inner and outer O±rings from the piston. 2. REMOVE PLATES, DISCS AND, FLANGE
± AUTOMATIC TRANSAXLEComponent Parts (Overdrive Unit) (A540E and A540H)AT±291
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DISASSEMBLY OF OVERDRIVE DIRECT
CLUTCH
1. CHECK PISTON STROKE OF DIRECT CLUTCH
Using a dial indicator, measure the piston stroke while apply-
ing and releasing the compressed air (4 ± 8 kg/cm2,
57 ± 114 psi or 392 ± 785 kPa) as shown.
Piston stroke: 1.75 ± 2.49 mm
(0.0688 ± 0.0980 in.)
SST 09350±32014 (09351±32190)
If the piston stroke is greater than the maximum, inspect
each component.
2. REMOVE OVERDRIVE DIRECT CLUTCH PROM CASE
3. REMOVE BEARING AND RACE FROM CLUTCH DRUM
AND CASE
4. REMOVE SNAP RING WITH SCREWDRIVER
5. REMOVE FLANGES, DISCS AND PLATES
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7. REMOVE PISTON FROM CLUTCH DRUM
(a) Install the clutch drum on the case.
(b) Apply compressed air to the pressure apply hole of the
case.
(c) Remove the piston from the clutch drum.
If the piston does not come out completely, use
needle±nose pliers to remove it.
(d) Remove the clutch drum from the case.
INSPECTION OF OVERDRIVE DIRECT
CLUTCH
1. INSPECT OVERDRIVE DIRECT CLUTCH
(a) Check that the check ball is free by shaking the piston.
(b) Check that the valve does not leak by applying low±
pressure compressed air. 6. REMOVE PISTON RETURN SPRING
(a) Place SST on the spring retainer and compress the
spring with a shop press.
SST 09350±32014 (09351±32070, 09351±32200)
(b) Remove the snap ring.
8. REMOVE O±RINGS
Remove the two O±rings from the piston. (c) Remove the piston return spring.
± AUTOMATIC TRANSAXLEComponent Parts (Overdrive Unit) (A540E and A540H)AT±293
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2. INSPECT DISCS, PLATES AND FLANGES
Check if the sliding surfaces of the discs, plates and
flanges are worn or burnt. If necessary, replace them.
HINT:
wIf the lining of the disc is exfoliated or discolored, or
even a part of the printed numbers are defaced, re-
place all discs.
wBefore assembling new discs, soak them in ATF for
at least fifteen minutes.
3. CHECK DIRECT CLUTCH BUSHING
Using a dial indicator, measure the inside diameter of
the two direct clutch bushings.
Maximum inside diameter: 22.13 mm (0.8713 in.)
If the inside diameter is greater than the maximum, re-
place the direct clutch drum.
ASSEMBLY OF OVERDRIVE DIRECT
CLUTCH
1. INSTALL CLUTCH PISTON
(a) Install new O±rings to the piston. Coat the O±rings
with ATF.
2. INSTALL PISTON RETURN SPRING
(a) Install the return spring and set snap ring in place.(b) Press the piston into the drum with the cup side up, being
careful not to damage the O±ring.
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(b) Place SST on the spring retainer, and compress the
spring with a shop press.
SST 09350±32014 (09351±32070, 09351±32200)
(c) Install the snap ring with a screwdriver. Be sure end gap
of snap ring is aligned with the groove of the clutch
drum.
5. INSTALL BEARING AND RACE
(a) Coat the bearing with petroleum jelly and install it fac-
ing the race side downward to the clutch drum.
Bearing: outer diameter 46.3mm (1.823 in.)
Inner diameter 26.2mm (1.031 in.)
(b) Coat the race with petroleum jelly and install it to the case.
Race: Outer diameter 43.0mm (1.693 in.)
Inner diameter 24.5mm (0.965 in.) 4. INSTALL SNAP RING
Be sure end gap of the snap ring is not aligned with the
groove of the clutch drum. 3. INSTALL PLATES, DISCS AND FLANGE
Install in order: P=Plate D=Disc
P±D±P±D±Flange
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DISASSEMBLY OF COUNTER DRIVE GEAR
1. CHECK OPERATION OF ONE±WAY CLUTCH
(a) Install the overdrive direct clutch into the one±way clutch.
(b) Hold the overdrive direct clutch and turn the intermediate shaft.
The shaft should turn freely clockwise and should lock coun-
terclockwise.
(e) Remove the overdrive direct clutch. 7. RECHECK PISTON STROKE OF DIRECT CLUTCH
Using a dial indicator, measure the piston stroke while applying
and releasing the compressed air (4 ± 8 kg/cm2,
57 ± 114 psi or 392 ± 785 kPa) as shown.
Piston stroke: 1.75 ± 2.49mm
(0.0689 ± 0.0980 in.)
SST 09350±32014 (09351±32190)
(b) Using a tension gauge, measure the preload.
Preload (at starting) : 940 ± 1,560 g
(2.1 ± 3.4 lb, 9.2 ± 15.3 N)
HINT: Turn the counter drive gear right and left
several times before measuring the preload. 2. CHECK COUNTER DRIVE GEAR PRELOAD
(a) Hold the overdrive planetary gear in a vise with soft
jaws.
HINT: Do not let the counter drive gear touch the vise. 6. INSTALL DIRECT CLUTCH ON CASE
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4. REMOVE NO. 3 PLANETARY THRUST WASHER
5. REMOVE PLUGS FROM PLANETARY GEAR
Remove the four plugs with a magnetic finger.
HINT: Be careful not to lose them. 3. REMOVE O/D ONE±WAY CLUTCH AND OUTER RACE
(a) Remove the snap ring.
(e) Remove the O/D one±way clutch from the outer
race.
HINT: Note the direction of the one±way clutch. (b) Remove the retaining plate.
(c) Remove the O/D one±way clutch with outer race.
(d) Remove the two retainers from both sides of the
O/D one±way clutch.
± AUTOMATIC TRANSAXLEComponent Parts (Overdrive Unit) (A540E and A540H)AT±297