Garage411 : ATOverhaul2FD3S

Mazda RX-7 Automatic Transmission Overhaul Part 2: valve body, clutch, brake bands and etc

Mazda RX7 1993-1995 FD3S

RA4A-EL, RA4AX-EL and RB4A-EL


Mazda RX-7 RA4A-EL, RA4AX-EL and RB4A-EL Overhaul



TORQUE CONVERTER


INTRODUCTION

Inspection
The torque converter is a sealed unit and cannot be disassembled for service. Remove any rust from pilot hub and boss of converter. If hub of converter is scored or if metal particles are found in transmission fluid, replace torque converter.

Cleaning
Flush inside of converter first with solvent and then ATF.

TRANSMISSION DISASSEMBLY
1. Remove torque converter. Remove transfer case on 4WD and adaptor housing. Remove transmission range switch and vehicle speed sensor. Unbolt harness connector bracket (if applicable). Remove oil pan. See Fig. 12 . Remove output speed sensor. Remove bolts from extension housing. Note location and length of bolts.
2. Remove input/turbine speed sensor. Remove clip from solenoid valve and TFT sensor harness connector. See Fig. 13. Remove TFT sensor. Remove oil strainer and "O" ring. Remove solenoid harness from clips. Remove valve body with oil pipes. Remove accumulator springs. Remove solenoid connector from transmission case. Remove converter housing and "O" rings from transmission case. Remove "O" ring from input shaft.
3. Install 2 slide hammers into oil pump housing and applying even pressure on both slide hammers, remove oil pump. Pull out input shaft while holding reverse drum. Loosen anchor end bolt lock nut and remove anchor end bolt. Do not reuse anchor end bolt. Remove brake band with strut and secure OD band with a wire clip.
4. Remove reverse clutch, high clutch and front sun gear as an assembly. See Fig. 14 . Remove front planetary carrier, bearings and rear sun gear. Remove snap ring and speedometer drive gear with key or steel ball (as applicable). Remove front snap ring. Remove snap ring from output shaft and remove parking gear with bearing. Pushing output shaft forward, remove front snap ring from output shaft. Remove output shaft.
5. Remove front internal gear with rear planetary carrier, rear internal gear, forward clutch hub and overrunning clutch as an assembly. See Fig. 14 . Remove forward clutch drum (forward clutch, overrunning clutch, low one-way clutch) from case.

Fig. 12: Exploded View Of Transmission External Components and Valve Body (RX7 and 929 Shown, MPV Similar)
Fig.12
Fig. 13: Disconnecting Solenoid Valve & TFT Sensor Harness Connector Clip
Fig.13
Fig. 14: Exploded View Of R4A-EL Series Transmission Internal Components
Fig.14
ACCUMULATORS

Disassembly
Remove accumulator pistons by applying air pressure through oil passages. See Fig. 15 . Remove "O" rings from pistons, clean grooves, check spring free length.

Reassembly
Install "O" rings on accumulator pistons. Place N-D accumulator spring in case and install pistons. See Fig. 16. Match springs to correct pistons.

ACCUMULATOR SPRING FREE LENGTH


Fig. 15: Identifying Transmission Fluid Passages
Fig.15
Fig. 16: Exploded View Of Low and Reverse Brake and Accumulators
Fig.16
OIL PUMP

Disassembly
Remove oil seal, loosen oil pump cover bolts evenly in sequence. See Fig. 17. Remove oil pump cover, mark rotor and cam ring. Do not use punch to mark parts. Separate rotor, vane ring and vanes. Wrap screwdriver tip with tape. On spring side of cam ring, push cam ring towards spring. Remove pivot pin. Holding spring, remove screwdriver and cam ring.

Inspection
1. Install NEW seal ring and ensure clearance between seal ring and ring groove is .004-.010" (.10-.25 mm). If not within specification, replace oil pump as an assembly.
2. Install cam ring vanes, rotor and control piston. DO NOT install friction ring, "O" ring, control piston side seals, or cam ring spring. Measure clearance between oil pump surface to cam ring, rotor, vanes and control piston in 4 places around oil pump. See Fig. 18. Cam ring spring free length should be 1.57" (39.8 mm).

Reassembly
Install oil seal in oil pump housing. To reassemble, reverse disassembly procedure. Tighten mounting bolts evenly in crisscross pattern to specification.

OIL PUMP SPECIFICATIONS

Fig. 17: Exploded View Of Oil Pump
Fig.17
Fig. 18: Checking Oil Pump Clearance
Fig.18
REVERSE CLUTCH

Disassembly
1. Remove snap ring, retainer plate, drive plates, driven plates and dish plate. See Fig. 19 . Compress spring retainer and remove snap ring. Remove spring retainer and springs.
2. Place reverse clutch hub on oil pump hub support, apply air pressure to reverse clutch pressure oil passage to remove reverse clutch piston. See Fig. 20 . Remove and discard "O" ring and seal on piston.

Inspection
Replace drive plates (friction discs) is thickness if less than .071" (1.8 mm). Check for broken or weak return springs. Check spring and retainer assembly for separation or deformation. Measure return spring free length. Length should be .78" (19.7 mm). Ensure check ball in clutch piston allows air to flow in one direction only.

Reassembly
1. Install NEW "D" ring into piston groove. Install NEW seal ring on piston. Ensure lip of seal faces away from spring side. Soak NEW friction discs in ATF prior to assembly.
2. Lubricate seal surface in reverse drum and install reverse clutch. Install return springs and spring retainer. Compress spring retainer and install snap ring.
3. Install dished plate. See Fig. 19 . Install drive and driven plates, retaining plate and snap ring. Measure clearance with feeler gauge between snap ring and retaining plate. Clearance should be .020-.047" (.50-1.20 mm). See Fig. 21 .
4. Adjust clearance by installing selective retaining plate. Retaining plates range in thickness from .185" (4.60 mm) to .228" (5.80 mm) in .008" (.20 mm) increments.
5. Place oil pump on bench with seal rings installed. Place reverse clutch on oil pump. See Fig. 20 . Apply 57 psi (4 kg/cm2 ) air pressure to appropriate oil passage and check clutch operation.

Fig. 19: Exploded View Of Reverse Clutch
Fig.19
Fig. 20: Removing and Checking Clutch Pistons and Identifying Oil Pump Passages
Fig.20
Fig. 21: Measure Reverse Clutch Clearance
Fig.21
HIGH CLUTCH

Disassembly
1. Remove front sun gear with bearing race and bearing. Remove high clutch hub with bearing and bearing race. Remove snap ring, retainer plate, drive and driven plates. See Fig. 22.
2. Compress retainer ring and snap ring. Release press and remove retainer ring and springs. Place high clutch drum on oil pump. See Fig. 20 . Apply air pressure to high clutch oil passage to remove piston. Remove inner and outer "D" rings from piston and discard.

Inspection
Replace drive plates (friction discs) is thickness if less than .055" (1.40 mm). Check for broken or weak return springs. Check spring and retainer assembly for separation or deformation. Measure return spring free length. Length should be .87" (22.1 mm). Ensure check ball in clutch piston allows air to flow in one direction only.

Reassembly
1. Install NEW "D" rings on piston and install piston in drum. Install return springs and spring retainer. Compress spring retainer and install snap ring. DO NOT align snap ring gap with spring retainer stop.
2. Install drive and driven clutches into high clutch drum. See Fig. 22 . Install retaining plate and snap ring. Measure clearance between snap ring and retaining plate. See Fig. 23 . Clearance should be .071-.118" (1.80-3.00 mm). See Fig. 21 .
3. Adjust clearance by installing selective retaining plate. Retaining plates range in thickness from .118" (3.00 mm) to .189" (4.80 mm) in .008" (.20 mm) increments.
4. Place high clutch on oil pump. Apply 57 psi (4 kg/cm2 ) air pressure to appropriate oil passage and check clutch operation. See Fig. 20 .
5. Apply petroleum jelly to front and rear bearing races and install in high clutch hub. Apply petroleum jelly to needle bearing and install in high clutch hub. See Fig. 22 .
6. Install high clutch hub into high clutch by turning to align clutch driven plates. Apply petroleum jelly on needle bearing and bearing race for front sun gear. Install needle bearing inside front sun gear. Install bearing race over front sun gear. Install front sun gear on high clutch hub.

Fig. 22: Exploded View Of High Clutch
Fig.22
Fig. 23: Measuring High Clutch Clearance
Fig.23
BRAKE BAND SERVO

Disassembly
1. Remove 4 cap screws from band servo retainer and remove cover. See Fig. 24 . Apply air pressure to cover to remove piston.
2. Apply air pressure in 2nd gear servo oil passage to remove band servo piston and retainer. See Fig. 15. Remove retaining ring from piston stem. Remove spring retainer and return spring "C".
3. Separate servo piston retainer from band servo piston. Remove larger retaining ring from piston stem. Remove piston stem from servo cushion retainer and band servo piston from servo cushion retainer. See Fig. 24 . Remove and discard all "O" rings and "D" rings.

Reassembly
To reassemble, reverse disassembly procedure. Lubricate NEW "O" rings and "D" rings with ATF. Install pistons by applying even pressure on perimeter of piston. Torque OD band servo retainer bolts to specification. Check operation by applying air pressure to oil holes. See Fig. 11 .

RETURN SPRING FREE LENGTH

Fig. 24: Exploded View Of Brake Band Servo
Fig.24
FRONT AND REAR INTERNAL GEARS, FORWARD CLUTCH HUB AND OVERRUNNING CLUTCH HUB

Disassembly
Remove front internal gear, bearing race, bearing, rear internal gear, thrust washer, bearing, overrunning clutch hub, thrust washer, snap ring and forward one-way clutch assembly. See Fig. 25 .

Inspection
Inspect gear teeth for damage, wear or cracks, and rotation of pinion gears. Inspect bearing races and bearings for smooth rotation, damage, scoring and scratches.

Reassembly
1. Install one-way clutch in forward clutch hub with arrow pointing forward. Install one-way clutch snap ring. See Fig. 26 . Apply petroleum jelly to thrust washer and place on rear internal gear.
2. Install rear internal gear on forward clutch hub and one-way clutch assembly by turning it clockwise. Check one-way clutch rotation. Holding forward clutch hub, rear internal gear should rotate clockwise only and lock counterclockwise. See Fig. 27 .
3. Apply petroleum jelly to bearing and install in rear internal gear. Apply petroleum jelly to thrust washer and set it in overrunning clutch hub, ensure tabs of thrust washer seat in holes in forward clutch hub. Install overrunning clutch hub on rear internal gear.
4. Apply petroleum jelly on bearing and set it on overrunning clutch hub. Apply petroleum jelly to bearing race and place on front internal gear pinion carrier side.



Fig. 25: Exploded View Of Front and Rear Internal Gear Assembly
Fig.25
Fig. 26: Installing One-Way Clutch
Fig.26
Fig. 27: Checking Forward One-Way Clutch Operation
Fig.27
FORWARD CLUTCH DRUM ASSEMBLY (FORWARD CLUTCH, OVERRUNNING CLUTCH AND LOW ONE-WAY CLUTCH)

Disassembly
1. Remove 2 snap rings in forward clutch drum, retaining plate, drive and driven plates, dished plate, snap ring for overrunning clutch, retaining plate, drive and driven plates and dished plate. See Fig. 28 .
2. Remove snap ring from low one-way clutch. Remove side plate, low one-way clutch snap ring and bearing. Press spring retainer and remove snap ring.
3. Place forward clutch drum in transmission case. Apply air to oil passage to remove overrunning clutch piston. See Fig. 15 . Apply air pressure to oil passage to remove forward clutch piston.

Inspection
Replace drive plates (friction discs) is thickness if less than .071" (1.80 mm). Check for broken or weak return springs. Check spring and retainer assembly for separation or deformation. Measure return spring free length. Length should be 1.41" (35.8 mm). Ensure check ball in clutch piston allows air to flow in one direction only.

Reassembly
1. Install bearing and snap ring in forward clutch drum. Install low one-way clutch with flange facing outward. See Fig. 28 . Install side plate and snap ring.
2. Install "D" rings and seal rings on forward clutch piston and overrunning clutch piston. Seal ring lip faces piston bore. Install overrunning clutch piston in forward clutch drum.
3. Align notches in forward clutch piston with grooves in forward clutch drum. Install overrunning clutch piston in forward clutch piston.

Apply ATF to all parts on reassembly except where noted.

4. Install return spring and retainer ring in forward clutch drum. Compress retainer ring and install snap ring with gap positioned away from stop.
5. Install dished plate, drive and driven plates, retaining ring and snap ring in correct order. See Fig. 28 . Using feeler gauge, measure clearance between snap ring and retainer plate. See Fig. 29 . Clearance should be .039-.079" (1.0-2.0 mm). Adjust clearance with selective retainer plates. Retaining plates range in thickness from .157" (4.00 mm) to .205" (5.20 mm) in .008" (.20 mm) increments.
6. Install dished plate, drive and driven plates, retaining ring and snap ring into forward clutch drum. See Fig. 28 . Using feeler gauge, measure clearance between snap ring and retainer ring. See Fig. 30 . Clearance should be .018-.081" (.45-2.05 mm) for MPV and .018-.073" (.45-1.85 mm) for RX7 and 929.
7. Adjust clearance with selective retainer plates. On MPV, retaining plates range in thickness from .157" (4.00 mm) to .205" (5.20 mm) in .008" (.20 mm) increments. On RX7 and 929, retaining
plates range in thickness from .315" (8.00 mm) to .362" (9.20 mm) in .008" (.20 mm) increments.
8. Install forward clutch drum in transmission case. Apply 57 psi (4 kg/cm2 ) air pressure to forward and overrunning clutch oil passages. See Fig. 15 . Check low one-way clutch operation. Forward clutch drum should turn clockwise only and lock counterclockwise. See Fig. 31 .

Fig. 28: Exploded View Of Forward Clutch Drum Assembly
Fig.28
Fig. 29: Measuring Overrunning Clutch Clearance
Fig.29
Fig. 30: Measure Forward Clutch Clearance
Fig.30
Fig. 31: Checking Low One-Way Clutch Operation
Fig.31

LOW AND REVERSE BRAKE

Disassembly
1. Remove snap ring, retainer plate, drive and driven plates. See Fig. 32 .
2. Using an Allen wrench, remove 4 bolts holding one-way clutch inner race to rear case. Hold inner race and return springs while removing last 2 bolts. Remove retainer and springs. Apply air to oil passage to remove low and reverse brake piston. See Fig. 15 .

Inspection
1. Check for broken or weak return springs. Check spring and retainer assembly for separation or deformation. Replace drive plates (friction discs) is thickness if less than .071" (1.80 mm). Measure spring free length. Length should be .933" (23.70 mm) on MPV and .878" (22.30 mm) on RX7 and 929.
2. Inspect low and reverse piston check ball. Ensure air flows from spring-seat side of piston. Air should not flow in reverse direction. Inspect bearings for damage and roughness. Replace as necessary.

Reassembly
1. Install "D" ring to inside channel of low and reverse piston. Install seal ring to outer channel of low and reverse piston with lip of seal facing away from spring side.
2. Install low and reverse piston in case. Apply petroleum jelly to seal rings. Install seal rings to low and reverse piston.
3. Position case with piston facing upward and set return springs in proper location. Install spring retainer with low one-way clutch inner race centered in spring retainer.
4. Ensure spring retainer remains over springs and is centered on low one-way clutch inner race. Install and tighten bolts in crisscross pattern to specification.
5. Install drive and driven plates, retainer and snap ring. See Fig. 32. Using feeler gauge, measure clearance between snap ring and retainer plate. See Fig. 33 .
6. Clearance should be .028-.091" (.70-2.30 mm) for MPV, .031-.102" (.80-2.60 mm) for RX7 or .031-.094" (.80-2.40 mm) for 929.
7. Adjust clearance with selective retainer plates. On RX7, retaining plates range in thickness from .244" (6.20 mm) to .315" (8.00 mm) in .008" (.20 mm) increments. On MPV and 929, retaining
plates range in thickness from .354" (9.00 mm) to .394" (10.00 mm) in .008" (.20 mm) increments. Apply 57 psi (4 kg/cm2 ) air pressure to oil passage and check low and reverse clutch operation. See Fig. 15 .

Fig. 32: Exploded View Of Low and Reverse Clutch
Fig.32
Fig. 33: Measuring Low and Reverse Brake Clearance
Fig.33
EXTENSION HOUSING (4WD ADAPTER CASE) AND PARKING MECHANISM

Disassembly
1. Unlatch parking return spring, remove spacer and parking pawl. Remove parking actuator bolts, parking actuator and parking rod guide. See Fig. 34 and Fig. 35.
2. Remove lock nuts from manual shaft, remove manual plate, parking rod, roll pin and manual shaft. Remove bolts from spacer and detent spring.
3. Remove oil seals from transmission case for manual shaft and from extension housing or adaptor case.

Inspection
Check parking gear for teeth damage or wear. Check output shaft splines for wear or damage. Check detent spring for fracture or wear. Check transmission inner bearing for damage or rough rotation.

Reassembly
Install output shaft oil seal. Wrap tape around manual shaft threads and install manual shaft. Seat manual shaft seal into case and remove tape from manual shaft. Install roll pin to an installed height of .20" (5.0 mm). To reassemble, reverse disassembly procedure.

Fig. 34: Exploded View Of Extension Housing (MPV Shown, RX7 and 929 Similar)
Fig.34
Fig. 35: Identifying Park Mechanism Components
Fig.35
VALVE BODY

CAUTION: All valve body components must be installed in original location. Lay all components in sequence during removal for reassembly reference. Clean all parts with solvent and dry with compressed air. Clean all holes and passages and blow dry with compressed air. DO NOT wipe parts with shop towel.

Disassembly
Remove all solenoids. Remove retaining bolts and nuts, brackets, lower valve body, steel balls, upper gasket, separator plate, lower gasket, orifice check valve with spring, pilot filter and manual valve. See Fig. 36 and Fig. 37 . Disassemble lower and upper valve body. See Fig. 38 -Fig. 41 .

Inspection
Inspect all parts for scratches and free movement in bores; valves should slide out on their own weight. Check spring free length. Replace parts as necessary. Replace all "O" rings on solenoid valves.

Reassembly
To reassemble, reverse disassembly procedure. Ensure all parts are installed correctly. See Fig. 36 -Fig. 41. Ensure check balls are installed in correct location. During assembly of valve body, ensure bolts are installed in correct location. See Fig. 43 . Tighten bolts to specification.

Fig. 36: Exploded View Of Valve Body
Fig.36
Fig. 37: Identifying Lower Valve Body Filters
Fig.37
Fig. 38: Exploded View Of Lower Valve Body (MPV)
Fig.38
Fig. 39: Exploded View Of Lower Valve Body (RX7 and 929)
Fig.39
Fig. 40: Exploded View Of Upper Valve Body (MPV)
Fig.40
Fig. 41: Exploded View Of Upper Valve Body (RX7 and 929)
Fig.41
Fig. 42: Locating Lower Valve Body Check Balls
Fig.42
Fig. 43: Identifying Valve Body Bolt Location
Fig.43
VALVE BODY SPRING SPECIFICATIONS



Mazda RX-7 RA4A-EL, RA4AX-EL and RB4A-EL Overhaul

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Mazda RX7 1993-1995 FD3S

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