Muncie 4 (117MM) Speed

Disassembly










1. Mount transmission in suitable holding fixture and remove cap screws attaching transmission cover assembly to transmission case. If required, insert two 5/16 x 18 screws in cover flange threaded holes and turn evenly to raise cover dowel pins from case. Move reverse shifter fork so that reverse idler gear is partially engaged before attempting to remove cover. Forks must be positioned so rear edge of the slot in the reverse fork is in line with the front edge of the slot in the forward forks as viewed through tower opening.






2. Place transmission in two gears at once to lock gears. Remove the universal joint flange nut, universal joint flange and brake drum assembly. On models equipped with 4-wheel drive transfer case, use tool J-23070 to remove mainshaft rear lock nut.
3. Remove parking brake and brake flange plate assembly on model equipped with propeller shaft parking brake.
4. Remove rear bearing retainer and gasket.
5. Slide speedometer drive gear off mainshaft.
6. Remove drive gear bearing retainers and gasket.
7. Remove countergear front bearing cap and gasket.
8. Pry countergear front bearing out by inserting a two-pronged puller J-28509 through the cast slots in case.






9. Remove countergear rear bearing retainer rings (snap-rings) from shaft and bearing. Using tool J-22832 and J-8433-1, remove countergear rear bearings. This will allow countergear assembly to rest on bottom of case. Make sure tool J-22832 engages full circumference of groove in bearing to prevent tool damage.
10. Remove drive gear bearing outer race to case retaining ring.
11. Remove drive gear and bearing by tapping gently on bottom side of drive gear shaft and prying directly opposite against the case and bearing snap ring groove at the same time. Remove 4th gear synchronizer ring. Index cut out section of drive gear in down position with countergear to obtain clearance for removing clutch gear.






12. Remove rear mainshaft bearing retainer ring (snap-ring) using tool J-22832 and J-8433-1, remove bearing from case. Slide 1st speed gear thrust washer off mainshaft.
13. Raise rear of mainshaft assembly and push rearward in case bore, then swing front end up and lift from case. Remove synchronizer cone from shaft.
14. Slide reverse idler gear rearward and move countergear rearward until front end is free of case, then lift to remove from case.
15. To remove reverse idler gear, drive reverse idler gear shaft out of case from front to rear using a drive. Remove reverse idler gear from case.