Transmission Disassembly

1. On all models, remove release bearing, clutch release fork and dust boot. Remove front cover bolts, front cover, gasket, oil seal, clutch housing and adjustment shim(s). See Fig 1. On RX-7 models, remove bolt, spring and lock ball from extension housing. Remove control case cover and select lock spindle.
2. On B2600 models, remove control cover assembly. Remove spring pin from control lever end. Remove transfer case (if equipped) and input sleeve. On all models, remove extension housing attaching bolts. On RX-7 models, DO NOT  remove change control case. On all models, 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. On RX-7, remove dynamic damper lock nut, taper cotter, dynamic damper and steel ball.
4. Drive out spring pins attaching shift rod ends to shift rods. Remove shift rod ends. See Fig 2. 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 R-Type Transmission Rear Section

   Courtesy of MAZDA MOTORS CORP.
   Fig 2: Exploded View Of R-Type Transmission Intermediate Section

   Courtesy of MAZDA MOTORS CORP.
5. Remove mainshaft rear bearing using Bearing Puller (490839425C). On B2600 models, label front or rear "C" washers for reassembly reference. On RX-7 models, remove remaining "C" washer, retaining ring, thrust lock washer and lock ball. On all models, 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.
   NOTE: 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 spring pin from 3rd/4th shift fork and slide 3rd/4th shift rod out rear of transmission case. Drive spring pin from 1st/2nd shift fork and slide 1st/2nd shift rod out of transmission. See Fig 2.
8. From end of mainshaft, remove thrust lock washer, lock ball, 5th gear, needle bearings and synchronizer ring. See Fig 2. Uncrimp tabs of lock nut, shift into 1st and reverse gear to lock mainshaft and remove using Lock Nut Wrench (491243465A). Discard lock nut.
9. Remove bearing cover bolts. Attach bearing puller and Hook (490187520), to bearing cover. Remove assembly containing 5th/reverse hub assembly, synchronizer ring, needle bearing, inner race, reverse gear and thrust washers. See Fig 2. Remove thrust washers, reverse idle gear shaft, reverse idle gear and remaining thrust washers.
10. Remove mainshaft center bearing using bearing puller. Remove 1st gear. See Fig 3. 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 3: Exploded View Of Mainshaft & Countershaft Assemblies

Courtesy of MAZDA MOTORS CORP.