MUNCIE 5LM60 (HM-290) 4 & 5 Speed

Fig. 1 Two Wheel Drive Transmission Gear Components:

Fig. 2 Two Wheel Drive Transmission Shift Mechanism And Case Components:

1. Install pilot bearing (3) into input shaft (1) with smaller diameter of bearing cage toward input shaft. Retain with petroleum jelly.
2. Install input shaft (1), pilot bearing (3), synchronizer ring (2) and mainshaft assembly (4) into assembly pallet tool No. J-36515.
3. Install countershaft adapter tool No. J-36515-12 onto countershaft (53) (5 speed) or (54) (4 speed). Install assembly onto assembly pallet tool No. J-36515.
4. Install reverse idler assembly (46) and new O-ring (52).
5. Install bearing assembly outer race (37) and ball bearing outer race (38).
6. Install the following on mainshaft assembly (4) or (5): 3-4 shift fork (108) (with taper on fork towards 3rd gear), 1-2 shift rail assembly (100). On 4 speed models only, install reverse shift rail assembly (111) and spacer block (115). Lock up transmission by sliding 3-4 shift fork (108) and 1-2 shift rail assembly downward towards Assembly Pallet tool No. J-36515.
7. Install 4mm ball (40) on output shaft and retain with petroleum jelly.
8. Install inner threaded thrust ring (41) and outer threaded thrust ring (39). Ensure that old spiral roll pin (42) is removed from outer threaded thrust ring (39). Install ring as follows:
a. Screw rings completely together, then back of rings until both ID slots for ball (40) line up.
b. Slide assembled rings over ball retained on output shaft.
c. Slide rod on output shaft spanner tool No. J-36516, turn black depth locating tang over and slide rod through.
d. Make clearance for snap ring by first screwing rings completely together by turning output shaft spanner tool No. J-36516 counterclockwise.
9. Install new snap ring (43).
10. Turning output shaft spanner tool No. J-36516 clockwise, torque thrust ring to 12 ft. lbs., then advance to next spiral roll pin notch. Hold countershaft against mainshaft while setting torque.
11. Install new spiral roll pin (42) as follows:
a. Install roll pin in bottom of output shaft spanner tool No. J-36516.
b. Install output shaft spanner tool No. J-36516 with roll pin hole and roll pin lined up.
c. Drive roll pin into outer thrust ring, then remove tool.
12. Install speed sensor rotor (45). Heat rotor to 250°F for 7-10 minutes prior to installation.
13. Install shim (212) onto output shaft bearing assembly (33) and retain with petroleum jelly. 2 wheel drive rear housing output shaft bearing assembly bore must be heated with a heat gun for 3-5 minutes prior to assembly.

Fig. 11 Installing Rear Housing. Two Wheel Drive Models:

14. Install output shaft bearing retainer alignment cables tool No. J-36515-10 through bolt holes (304, 305) in rear housing, Fig. 11, screw into output shaft bearing retainer (302). Ensure that notch in retainer is towards oil delivery tube assembly (307).
15. Install bearing (203) into bearing race (202) of housing. Place smaller diameter of bearing cage into bearing race and retain with petroleum jelly. Press each roller towards the race to secure them for easier assembly.
16. Install rear housing assembly (300), ensuring that reverse idler shaft is lined up with hole in case. Pull up on output shaft bearing retainer alignment cables tool No. J-36515-10 while installing rear housing. Bring housing straight down. If resistance is felt at about 1/4 inch, then rollers are cocked. Repeat above procedures to install. Do not force housing down. Remove output shaft bearing retainer alignment cables tool No. J-36515-10 when housing is installed.
17. Install rear housing bolts (304) and (305), applying pipe sealant GM P/N 1052080 or equivalent to bolt holes of rear housing. Apply Loctite to bolt threads. Torque bolts (304, 305) to 17 ft. lbs.
18. Install rear housing assembly (301), ensuring that reverse idler shaft is lined up with hole in case. Bring housing straight down, if resistance is felt at about 1/4 inch, then rollers (35) or (203) are cocked. Repeat above procedures to install, do not force housing down.
19. Install ball bearing outer race (38).
20. Install 4mm ball onto output shaft, retain with petroleum jelly.
21. Install inner threaded thrust ring (41) and outer threaded thrust ring (39). Ensure that old spiral roll pin is removed from outer ring. Screw rings together completely, then back rings off until both ID slots for ball (40) line up. Slide assembled rings over ball retained on output shaft. Slide rod of output shaft spanner tool No. J-36516 up, turn black depth locating tang over and slide rod through, thus installing roll pin to correct depth. Make clearance for snap ring by first screwing rings together completely by turning output shaft spanner tool No. J-36516 counterclockwise.
22. Install a new 2mm thick snap ring (43).
23. Turning output shaft spanner tool No. J-36516 clockwise, torque to 12 ft. lbs., then advance to next spiral roll pin notch.
24. Install new spiral roll pin (42) as follows:
a. Install roll pin in bottom of output shaft spanner tool No. J-36516, retain with petroleum jelly.
b. Install output shaft spanner tool No. J-36516 with roll pin hole and roll pin lined up.
c. Drive roll pin into thrust ring (outer).
d. Remove tool, then install seal protector onto output shaft.
25. Install output shaft oil seal (320) using seal installer tool No. J-36502. Fill area between seal lips with chassis grease, then remove seal protector.
26. Lay unit down horizontally and remove assembly pallet tool No. J-36515, then install idler shaft support (310) and bolt (311) as follows:
a. Line up bolt threads in idler shaft support with bolt hole. Machined surfaces on face of casting must be installed down into case because bolt hole is slightly off center. Incorrect installation will cause incorrect reverse gear tooth pattern under load.
b. Apply pipe sealant 1052080 or equivalent to bolt hole.
c. Apply Loctite to bolt threads.
d. Hold reverse idler shaft against idler support while tightening, torque bolt (311) to 17 ft. lbs.
e. Install holding fixture tool No. J-8763-21 on tool No. J-8763-02 or equivalent.
27. Install holding adapter tool No. J-36824 onto transmission case, then place holding fixture tool No. J-8763-02 onto holding adapter tool No. J-36824.

Fig. 13 Installing Interlock Balls And 3-4 Shift Rail:

28. Install two interlock balls (323), Fig. 13, as follows:
a. Place all forks in neutral position and coat balls with petroleum jelly.
b. Using a magnetic screwdriver, insert interlock balls (one at a time) through plug hole.
c. Using a small blade screwdriver, push one ball to the 1-2 shift rail side and the other to the 3-4 shift rail side.
29. Install 3-4 shift rail (109) with interlock pin (110) as follows:
a. Retain pin with petroleum jelly.
b. Ensure that detent slots in 3-4 shift rail are up.
c. Install through 3-4 shift fork and into the rear housing shift rail bearing.
d. 1-2 and 5-reverse shift rail must be in neutral position or interlock system will not allow 3-4 rail to engage.
30. Install 36mm roll pin (107) to a depth where a maximum of 12.5mm (measured from edge of 3-4 rail to top of roll pin) is left remaining. If roll pin is not at proper depth, it may rub on front housing and cause 3rd or 4th gear hop out. Ensure interlock balls are in place by trying to move two shift rails.
31. Coat edge of new plug (326) with gasket maker 1052943 or equivalent, then install plug flush.

Fig. 14 Installing Shift Shaft:

Fig. 15 Installing Rollers:

Fig. 16 Installing Front Housing:

32. Install shift shaft (116), finger (121) and shift shaft socket assembly (123), Fig. 14.
33. Install three detent balls (323) and three springs (324).
34. Install detent spring cover (325) and two bolts (236). Apply gasket maker 1052943 or equivalent to outside of bolt hole pattern of detent spring cover. Torque bolts (236) to 7 ft. lbs.
35. Install four rollers (118) and retain with petroleum jelly, Fig. 15.
36. Install countershaft bearing (203) in bearing race (202) of front housing, Fig. 16. Smaller diameter of bearing cage is placed against bearing race. Retain with petroleum jelly and press on each roller towards outside of bearing race to lock it in place. Apply petroleum jelly to bearing race on input shaft.
37. Install roller bearing (218) and ball bearing outer race (217). Apply gasket maker 1052943 or equivalent to outside of bolt hole pattern of rear housing.
38. Install front housing (200). Bring housing straight down, if resistance is felt at about 1/4 inch, then rollers are cocked. Repeat steps 37, 38 and 39. Do not force housing down.
39. Install two dowels (321).
40. Install bolts (312). Do not tighten.

Fig. 17 Installing Input Shaft Bearing Retainer Assembly:

41. Install ball bearing outer race (215), input shaft spacer (211) and new selective snap ring (210), Fig. 17 as follows:
a. Install thickest snap ring that will fit.
b. If necessary, pull out on input shaft to install selective snap ring.
c. Apply gasket maker 1052943 or equivalent to inside of cover bolt hole pattern. Do not apply excessive gasket maker around oil drain back hole, this may restrict oil flow through bearing and lead to premature bearing failure.
42. Install shim (212) into input shaft bearing retainer assembly (205). Ensure that input bearing retainer washer (208) is in place. Retain with petroleum jelly.
43. Install input shaft bearing retainer assembly (205) and six bolts. Ensure that oil drain back hole is lined up with hole in housing. Torque bolts to 7 ft. lbs.
44. Install shift shaft detent plunger (243), shift shaft detent spring (244) and plug (245) using a brass drift. Apply pipe sealant 1052080 or equivalent to plug.
45. Install new O-ring (315) onto electronic speed sensor assembly (316) (2 wheel drive models only). Coat O-ring with a thin coat of transmission oil.
46. Install electronic speed sensor assembly and bolt. Torque bolt to 7 ft. lbs.
47. Install back-up lamp switch assembly (313). Apply pipe sealant 1052080 or equivalent to threads, then torque switch to 7 ft. lbs.
48. Remove holding fixture tool No. J-8763-02 and holding adapter tool No. J-36824.
49. Install transmission case bolts (312). Torque to 27 ft. lbs.