New Venture Gear 3500 (RPO MG5 & M50) 5-Speed

1. Remove idler shaft support bolt (311) and bottom two bolts. Refer to images to aid in disassembly and assembly of transmission.






2. Install tool J-8763-21 to J-8763-02, then install J-36824 onto transmission case. Install J-8763-02 to J-36824.

3. Remove back-up lamp switch assembly.

4. Remove bolt (317) and electronic speed sensor assembly (314, 2WD models only).

5. Remove detent plug (245) using J-36509 and J-23907 or equivalent, then remove spring (244) and plunger (243).

6. Remove two bolts (236), detent spring cover (325), springs (324) and balls (323).

8. Position unit vertically and remove six bolts (204) and input shaft retainer assembly (205). Save input bearing retainer washer (208).

9. Remove selective snap ring (210), input shaft spacer (211), ball bearing inner race (215) and shim (212), then position horizontally.

10. Remove front housing to rear housing bolts (312) and drive dowels (321) from front housing, then remove front housing (200).

11. Remove countershaft bearing (203).

12. Remove ball bearing inner race (217) and roller bearing (218).

13. Remove idler shaft support (310) and four rollers (118), then remove roll pin (120) by pulling shift shaft forward and cocking it to detent cover side. Support shift shaft end while driving out finger roll pin. Slide shaft all the way back and cock over to detent spring cover side.

14. Remove shift shaft socket assembly roll pin (122). Pin will fall into case. Do not use excessive force as this will "peen" shift shaft and damage rear housing shift shaft bearing, causing increased shift effort.

15. Remove shift shaft (116), shift shaft socket assembly (123) and finger (121).

16. Remove 3rd and 4th shift fork roll pin (107) using large pair of diagonal cutters to pry it out. If roll pin (107) breaks off, place transmission in 3rd gear, cut off remainder of roll pin and drive through.

17. Remove plug (326) by hitting it on one side, thus cocking it.

18. Remove 3rd and 4th rail (109) as follows:

a. Ensure 1-2 and 5-reverse rails are in neutral.

b. Drive through the plug hole (326) enough to expose roll pin hole (107), then insert punch and pull out shift rail while twisting it.






19. Install J-36515 with J-36515-12, and remove J-8763-02 and J-36824. Remove two interlock balls (323).






20. Remove and disassemble rear housing as follows:

a. Remove bolts (304) and (305).

b. Remove rear housing assembly.

c. Remove output shaft bearing retainer (302).

d. Remove shim (212). Lock up transmission in 2nd and 4th gear by sliding 1st-2nd rail assembly (100) and 3rd-4th shift fork (108) downward towards J-36515. Slide snap ring (43) and washer away from rotor to make clearance for J-21427-01






e. Remove speed sensor rotor (45) using J-21427-01 and J-8105 or equivalent. Do not reuse rotor after removal.

f. Remove washer (44) and snap ring (43).

g. Remove spiral roll pin (42) using J-36516.






h. Remove snap ring (43), then threaded inner thrust ring (41), ball (40) and outer threaded thrust ring (39). Hold countershaft against mainshaft and turn J-36516 clockwise until both threaded thrust rings are completely apart.

i. Remove reverse idler gear assembly (53) (5 speed models).

j. Remove 1-2 shift rail assembly (100), 5-reverse shift rail assembly (111), 3-4 shift fork (108) and (4 speed) spacer block (115).

k. Remove mainshaft assembly (4). Leave synchronizer ring (2) on the 3-4 synchronizer (7) to prevent synchronizer detent balls from popping out.

l. Remove input shaft gear (1) and pilot bearing (3).