Garage411 : MTOverhaulR15DFD3S

Mazda RX-7 Manual Transmission Overhaul R15M-D

Mazda RX7 1993-1995 FD3S

CAUTION: Vehicle is equipped with Supplemental Restraint System (SRS). When servicing vehicle, use care to avoid accidental air bag deployment. SRSrelated components are located in steering column, center console and instrument panel. DO NOT use electrical test equipment on these circuits. If necessary, deactivate SRS before servicing components.
Disconnecting battery on models equipped with anti-theft radio require canceling of anti-theft operation. Refer to vehicle owner's manual to identify radio type.



TRANSMISSION DISASSEMBLY


1. Remove release bearing, clutch release fork and dust boot. Remove front cover bolts, front cover (bearing support), gasket, oil seal, clutch housing and adjustment shim(s). See Fig. 1 and Fig. 2 . Remove control case cover and select lock spindle.
2. Remove extension housing attaching bolts. Move control rod to Neutral position. Separate extension housing from transmission case. Remove undercover and gasket.
3. Remove speedometer drive gear snap ring from mainshaft and slide drive gear off mainshaft. Remove steel ball and remaining snap ring. See Fig. 1 and Fig. 2 .
4. Drive out roll pins attaching shift rod ends to shift rods. Remove shift rod ends. See Fig. 3 . Separate transmission case from bearing housing assembly by prying gently with a pry bar. Remove snap ring, washer retaining ring and "C" washers.

Fig. 1: Exploded View Of Transmission
Fig.1
Fig. 2: Exploded View Of Extension Housing
Fig.2
Fig. 3: Exploded View Of 5th/Reverse Gear and Housing Components
Fig.3
5. Using appropriate puller, remove mainshaft rear bearing. Remove remaining "C" washer, retaining ring, thrust lock washer and lock ball. Shift clutch hub assemblies into 1st and reverse gears to lock rotation of mainshaft. Remove countershaft rear lock nut. Using bearing puller, remove countershaft rear bearing. Remove counter 5th gear and spacer from countershaft. Remove center housing mounting bolts. Tap housing with a soft mallet to remove. Remove mainshaft front bearing snap ring from case.
6. Install Synchronizer Ring Holder (49F017101) between 4th gear synchronizer ring and synchromesh gear on mainshaft. Turn bearing snap rings so gap is at a 90 degree angle to case grooves. Remove input shaft bearing using bearing puller. Remove countershaft bearing snap ring from front of countershaft. Remove countershaft front bearing using bearing puller.

DO NOT reuse lock nuts after removing.

7. Remove 5th/reverse shift fork. Remove blind covers and gaskets. Remove 3 spring cap bolts, springs and balls for shift rod. Drive roll pin from 3rd/4th shift fork and slide 3rd/4th shift rod out rear of transmission case. Drive roll pin from 1st/2nd shift fork and slide 1st/2nd shift rod out of transmission. See Fig. 3 .
8. From end of mainshaft, remove thrust lock washer, lock ball, 5th gear, needle bearings and synchronizer ring. Uncrimp tabs of lock nut, shift into 1st and reverse gear to lock mainshaft and remove. Discard lock nut.
9. Remove bearing cover. Remove assembly containing 5th/reverse hub assembly, synchronizer ring, needle bearing, inner race, reverse gear and thrust washers. Remove thrust washers, reverse idler gear shaft, reverse idler gear and remaining thrust washers.
10. Remove mainshaft center bearing using bearing puller. Remove 1st gear. See Fig. 4 . Remove countershaft center bearing using bearing puller. Remove countershaft from transmission case. Remove input shaft from transmission case. Remove mainshaft and gear assembly from transmission case.

Fig. 4: Exploded View Of Mainshaft and Countershaft Assemblies
Fig.4

COMPONENT DISASSEMBLY AND REASSEMBLY


MAINSHAFT

Disassembly
1. Remove snap ring from front of mainshaft. In arbor press, place puller between 2nd/3rd gears. Press mainshaft through 3rd and 3rd/4th clutch hub assembly. See Fig. 4 .
2. Reposition mainshaft in press and remove 1st/2nd clutch hub and sleeve assembly. Remove 1st gear sleeve from rear of mainshaft. Remove inner race of countershaft bearing from countershaft.

Inspection
Place disassembled mainshaft in "V" blocks. Position a dial indicator to a smooth bearing surface and zero indicator. Rotate mainshaft and note reading. If mainshaft exceeds maximum runout, replace mainshaft. Inspect all gears, synchronizers, splines and surfaces for wear and/or damage.

Reassembly
Position mainshaft in arbor press. Install 2nd gear with needle bearings installed and 1st/2nd clutch hub assembly over mainshaft and press into place. Install 3rd gear, needle bearing and 3rd/4th clutch hub assembly and press into place. Install snap ring in front of mainshaft. Install inner race, needle bearing, 1st gear and thrust washer.

TRANSMISSION SPECIFICATIONS

SYNCHRONIZERS

Disassembly
Synchronizers were disassembled during mainshaft disassembly. The synchronizers all have similar shapes. Measure each component to ensure correct reassembly. See Fig. 5.

SYNCHRONIZER DIMENSIONS

Fig. 5: Measuring Synchronizer Dimensions
Fig.5
Inspection
1. Inspect synchronizer unit for worn or damaged parts. Install synchronizer ring evenly to gear cone and measure clearance between side faces of ring and gear with feeler gauge. See Fig. 6 . Standard clearance is .059" (1.5 mm). Minimum clearance is .031" (.8 mm), replace synchronizer ring or gear if not within specifications. Check clearance between control lever and gate of shift rod with a feeler gauge. Maximum clearance should be .031" (.8 mm).
2. Check synchronizer key springs for tension. Ensure that clutch sleeve slides easily on clutch hub. Check clearance between hub sleeve and release fork groove using feeler gauge. See Fig. 6 . Standard clearance is .008-.012" (.20-.30 mm). Clearance limit is .020" (.50 mm). Replace if not within specifications. Inspect reverse idler gear and shaft for wear and damage. Standard clearance is .001-.002" (.03-.05 mm). Limit is .006" (.15 mm).

Ensure synchronizer ring and clutch hub are properly aligned on press during reassembly procedure.

Reassembly
Ensure clutch hubs are facing correct direction. See Fig. 7 .

Fig. 6: Checking Synchro Ring & Hub Sleeve Clearance
Fig.6
Fig. 7: Aligning Clutch Hub
Fig.7
TRANSMISSION REASSEMBLY

1. Press inner race of countershaft rear bearings onto countershaft. Using Vernier calipers, measure depth of input shaft bearing bore in clutch housing (View "A"). Measure mainshaft bearing snap ring height (View "B"). See Fig. 8 . Difference between 2 measurements is required adjusting shim thickness.

Fig. 8: Determining Input Shaft Bearing Shim Thickness
Fig.8
2. Standard input shaft thrust play is .004" (.10 mm). Adjusting shims (5) are available from .012-.028" (.30-.70 mm) in .004" (.10 mm) increments. Measure depth of mainshaft center bearing in bore of transmission case using Vernier calipers (View "A"). See Fig. 9 . Measure mainshaft center bearing height (View "B"). Difference between 2 measurements is required adjusting shim thickness. Standard mainshaft thrust play is .004" (.10 mm). Adjusting shims are available in sizes of .004 and .012" (.10 and .30 mm).
3. Using Vernier calipers, measure depth of countershaft front bearing in bore of transmission case ("A"). Measure countershaft front bearing height ("B"). See Fig. 10 . Select adjusting shim for difference ("A" - "B" + shim) to equal bearing height .035-.039" (.90-1.00 mm). Adjusting shims are available in sizes of .004 and .012" (.10 and .30 mm).

Fig. 9: Determining Mainshaft Center Bearing Shim Thickness
Fig.9
Fig. 10: Determining Countershaft Bearing Shim Thickness
Fig.10
4. Install mainshaft in transmission case. Install 1st/2nd and 3rd/4th shift forks into grooves of clutch hub and sleeve assemblies. Apply molybdenum grease to needle bearings in input shaft. Install needle bearing and input shaft on front of the mainshaft. Install countershaft into case. Ensure all gears mesh correctly.
5. Using suitable pipe, drive on countershaft center bearing. Install predetermined mainshaft center bearing adjusting shim into bore of transmission case. Drive mainshaft center bearing onto mainshaft using suitable driver. Install bearing cover.
6. Install Synchronizer Holder (49F017101) between 4th gear synchronizer and synchromesh gear on main drive gear. Drive on input shaft bearing. Install snap ring to secure input shaft bearing. Place predetermined countershaft front bearing adjusting shim into bore of transmission case. Drive on countershaft front bearing.
7. Install reverse idler gear and shaft with a spacer on each side of the shaft. Install counter reverse gear (chamfer toward front) and spacer onto countershaft. Install thrust washer, reverse gear, synchronizer ring, inner race, needle bearing and clutch hub assembly. Shift transmission into 1st and reverse gear to lock rotation of mainshaft and install a NEW lock nut on mainshaft using Lock Nut Wrench (491243465A).
8. Check clearance between synchronizer key and exposed edge of the synchronizer ring. If clearance is not .079" (2.00 mm), install a selective thrust washer between mainshaft front and rear bearing. Selective thrust washers are available in sizes of .098" (2.50 mm), .118" (3.00 mm) and .138" (3.50 mm). Stake lock nut in place on mainshaft.
9. Install synchronizer ring, 5th gear and needle bearing. Install steel ball and thrust washer. See Fig. 3 . Install .118" (3.00 mm) thick "C" washer and hold them with retaining ring on mainshaft. Using a feeler gauge, measure clearance between "C" washer and thrust washer. Standard clearance is .004-.008" (.10-.20 mm). If clearance is not within specification, select proper thrust washer. See Fig. 11 . Thrust washers are available from .244-.264" (6.20-6.70 mm) in .004" (.10 mm) increments.

Fig. 11: Measuring Between Thrust Washer and "C" Washer
Fig.11
10. Identify shift rods for proper location. See Fig. 12 . Slide 1st/2nd shift rod into transmission case. Secure 1st/2nd shift forks to shift rods with NEW spring pins. Slide 2 Shift Fork Guides (490862350) into transmission case. Insert interlock 1st pin. Remove 3rd/4th shift fork guide. Slide 3rd/4th shift rod into transmission case. Secure 3rd/4th shift rod with NEW spring pins. Insert interlock pin and remove shift fork guide. Install 5th/reverse shift fork on clutch hub and slide shift rod into transmission case. Secure with NEW spring pins. Install shift rod ends on proper shift rods. Secure shift rod ends with NEW spring pins.
11. Install 2 blind covers and gaskets. Install 3 detent balls, springs and cap bolts. Apply sealant to transmission case and center housing. Install center housing, ensuring to align reverse idler gear shaft boss with hold bolt hole and install hold bolt with gasket. Install oil guide. Install spacer and counter 5th gear. Install rear countershaft bearing. Lock transmission into gear and install countershaft lock nut. Stake lock nut into countershaft keyway. Drive in mainshaft rear bearing using suitable driver.
12. Install "C" washers and retaining ring. Measure clearance between mainshaft "C" washers and groove in mainshaft using feeler gauge. See Fig. 13 . If clearance exceeds .004" (.10 mm), replace "C" washer.

"C" WASHER THICKNESS

Fig. 12: Identifying Shift Rods
Fig.12
Fig. 13: Checking Clearance Between "C" Washer and Groove
Fig.13
13. Apply thin coat of sealer on mating surfaces of bearing housing and center housing. Assemble using a soft mallet. Install shift rod ends to shift rods and install spring pins. Install speedometer drive gear, lock ball and snap ring on mainshaft. Apply thin coat of sealer on mating surfaces of clutch housing and transmission case. Install predetermined shim on input shaft and countershaft front bearings. Install clutch housing and torque bolts to specification.
14. Install oil seal into extension housing. Install control rod into extension housing. On 4WD, apply sealant to contact surfaces of bearing housing and extension housing. Install extension housing on bearing housing.
15. Install input sleeve. Coat mating surfaces of transfer case and extension housing with sealant. Guide control lever into position when transfer case is installed on extension housing. Install control lever end and secure with spring pin. Coat bolts with sealant, install bolts and torque to specifications. Apply sealant to control cover and transfer case. Install control cover to transfer case. Apply sealant to threads of bolts, install and torque to specifications.
16. Apply thin coat of sealant on mating surfaces of bearing housing and extension housing. Assemble with control lever positioned as far left as possible. Install and tighten bolts. Install select lock spindle, spring and cap by pushing select lock spindle down with control rod. Install gasket and under cover. See Fig. 1 .

Torque mounting bolts to specification. Install clutch release bearing, clutch release fork and dust cover.


TORQUE SPECIFICATIONS





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Mazda RX7 1993-1995 FD3S

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