168 Manual Drive Trains and Axles Copyright by Goodheart-Willcox Co., Inc. 1 2 3 4 5 7 9 10 12 13 6 8 19 16 17 18 24 25 27 28 14 15 22 20 23 26 21 4 11 11. Lock ball, spring and plug 12. Shift arm 13. Set bolt and lock plate 14. Shift lever shaft 15. Shift plug 16. Reverse pin 17. Retaining pin and plug 18. No. 5 shift rail 19. Interlock pin 1. Reverse fork and shift arm 2. 1-2 shift fork 3. 3-4 shift fork 4. Lock ball, spring and plug 5. Bracket bolt 6. No. 3 shift rail 7. No. 1 shift rail 8. C-ring 9. No. 2 shift rail 10. C-ring 20. Interlock pin 21. Interlock pin 22. C-ring 23. Interlock pin 24. Fifth-reverse fork 25. Reverse shift head 26. Lock balls 27. No. 4 shift rail 28. Reverse arm bracket Plug Gasket Clip Transmission cover O-ring Shifter shaft oil seal Plunger Screw To offset and gearshift levers Shifter shaft for shifting forward gears Fork Insert Reverse fork Internal reverse lever Pin Pin Arm Interlock plate Insert Fork Plate Spring Figure 8-19. Some internal shift linkages use multiple shift rails, as seen in this exploded view. Note that the lock ball, spring, and plug assemblies shown in the illustration serve as detents. These detent ball assemblies hold the rails into whatever gear is selected. Interlock pins make it impossible to move more than one rail at a time. (Chrysler) Figure 8-18. A single shifter shaft is used in some manual trans- missions. Note that the shaft extends out of the transmission cover, through the oil seal, and into the extension housing. In the transmission shown, the reverse gear is operated through a separate reverse lever. (Ford) A second type of internal shift linkage employs a series of rods, or shift rails, to operate the shift forks. See Figure 8-19. Many transmissions use this system. A shift fork is attached to each shift rail. In addition, the shift rails have notched units attached, directly or indirectly, to their outer ends. When the driver shifts gears, the bottom of the gear- shift lever catches in one of the shift rail notches. As a result, the shift rail and shift fork are moved and trans mission gears are changed. Manual Transmission Case The transmission case supports the transmission shafts and forms a reservoir for lubricant. It is the main housing, or structure, of the transmission. The front of the case attaches to the clutch housing. In some designs, the clutch housing and case are a single integral casting. In other designs, the case bolts to the back of the clutch housing, Figure 8-20.