Assembly

1. Position countershaft into transmission case through top opening.
2. Position input shaft with flats facing top and bottom into transmission case. Ensure that needle roller bearing is installed into input shaft.
3. Install fourth gear synchronizer ring on output shaft assembly, then hold the synchronizer blocker ring in place and position output shaft assembly into transmission case. Mate input and output shaft assemblies by positioning them at an upward angle.

Outer Shaft & Countershaft Bearing Protrusion:

4. Install output shaft center bearing outer race using a brass drift. Seat center bearing outer races, maintaining bearing position. The shoulder of the outer race should be approximately 0.078 inch above case wall.
5. Install countershaft center bearing using a brass drift. Maintain bearing position. Ensure that center bearing outer races are squarely positioned in bores. The shoulder of the outer race should be approximately 0.039 inch above case wall.
6. Position center bearing cover to transmission case with reference arrow pointing upward. Install and torque center bearing cover retaining bolts to 14-19 ft lbs. Ensure all center bearing cover retaining bolt heads are marked with an 8.
7. Position transmission with clutch housing facing upward. Install input shaft front bearing outer race using a brass drift. Ensure outer race is squarely positioned in the bore and that the output shaft is free of obstruction.

Front Bearing Cover Measurement B:

Front Bearing Cover Measurement A & C:

8. Install countershaft front bearing by hand. If any related parts are replaced, measure dimensions A, B, and C. After measuring all dimensions, select proper bearing shim to maintain endplay specifications.
9. To determine input shaft endplay shim thickness, proceed as follows.
a. Measure dimensions A and B.
b. Subtract dimension A from dimension B. Then, add 0.002-0.006 inch. This equals required shim thickness.

Input Shaft Shim Selection Chart:

c. Refer to the Input Shaft Shim Selection Chart to select the proper shim.
10. To determine countershaft endplay shim thickness, proceed as follows:
a. Measure dimension C, Then, subtract 0.006-0.010 inch. This equals required shim thickness.

Countershaft Shim Selection Chart:

b. Refer to the Countershaft Shim Selection Chart to select the proper shim.
11. If removed, install front bearing cover oil seal using front cover seal installer tool No. T77J-7025-G or equivalent. Remove any sealant residue remaining on mating surfaces of transmission and front cover. Tape input shaft splines to prevent damage to oil seal lip.
12. Apply a thin coat of oil to front cover oil seal lip. Position bearing shim and baffle plate into front cover (install shim with groove showing). Install spacer to transmission case countershaft front bearing bore. Use grease to retain shim, bearing cover and oil baffle during assembly.
13. Apply a 1/8 inch bead of silicone rubber No. D6AZ-19562-B or equivalent to front-cover and front cover retaining bolt threads. Install front bearing cover to transmission case. Install and torque bearing cover bolts to 9-12 ft lbs.
14. Position transmission horizontally in holding fixture and ensure transmission rotates freely.
15. Install ball, fifth gear sleeve and needle bearing.
16. Install fifth gear onto output shaft. Ensure longer collar of gear faces forward of the transmission. If necessary to remove the fifth/reverse fork shift rail, cover the detent ball and spring installation hold to prevent ball from being lost during removal.
17. If fifth/reverse shift fork rail was removed, insert detent ball and spring into installation hole. Using a drift, depress detent ball and spring below the fifth/reverse fork rail bore. Install fifth/reverse fork shift rail with detent notches facing detent ball, spring and retaining bolt hole. Remove drift, and push rail completely through fork bore until detent ball locks into first detent notch.
18. Install fifth/reverse synchronizer hub, sleeve, and fifth gear synchronizer blocker ring to fifth/reverse shift fork and rail assembly. Ensure longer flange is toward front of transmission. The reference mark on the synchronizer sleeve must be installed toward reverse gear side.
19. Position the fifth/reverse shift fork into the rearmost of the three detent positions. Install fifth/reverse shift fork and shift rail assembly to countershaft. Mate shift fork gate to fifth/reverse counter lever end. Install fifth/reverse fork and shift rail assembly with threaded fixing bolt bores aligned with each other.
20. Return shift fork to neutral gear position.
21. Apply suitable sealant to fifth/reverse shift rail fixing bolt threads. Install fifth/reverse shift rail fixing bolt. Torque bolt to 16-22 ft lbs.

Split Washer Selection Chart:

22. Install split washer onto countershaft. If clutch hub and/or counter reverse gear have been replaced, new split washers must be selected to maintain endplay within 0.00-0.002 inch. Measure endplay using a feeler gauge, then select replacement split washers. Ensure split washers are a matched set of identical thickness.
23. Install reverse gear thrust washer over countershaft (groove of washer toward split washer), then the reverse synchronizer blocker ring and needle bearings into counter reverse gear.
24. Install counter reverse gear and needle bearings onto countershaft as an assembly.
25. Install thrust washer on countershaft. Ensure reverse synchronizer blocker ring is in line with insert keys.
26. Press thrust washer forward against shoulder on countershaft. Maintain forward pressure against thrust washer and insert feeler gauge between thrust washer to obtain specified endplay. Counter reverse gear endplay should be 0.010-0.014 inch.

Thrust Washer Selection Chart:

27. Using the thrust washer selection chart, determine the correct select thrust washer to obtain specified endplay. If thrust washer replacement is necessary, reverse countershaft gear will need to be removed.
28. Install thrust washer, then place a temporary spacer (inner bore larger than 21 mm, outer bore less than 36 mm, 15-20 mm length) in place of countershaft bearing. Loosely install countershaft locknut to retain components.
29. Install reverse idler gear assembly. Apply sealant to reverse idler gear fixing bolt threads and torque to 58-86 ft lbs.
30. Install sleeve and reverse gear onto output shaft. Ensure longer flange of the reverse gear faces rearward to the transmission.
31. Position counter lever assembly to transmission and align to slot in fork. Install thrust washer and retaining ring, then apply sealant to counter lever fixing bolt and torque to 6-7 ft lbs.

Output Shaft Bearing Installation:

32. Install output shaft rear bearing using gear installing spacer tool No. T88T-7025-G, shaft adapter tool No. T75L-7025-P, shaft adapter screw tool No. T75L-7025-K, remover/replacer tube tool No. T75L-7025-B or remover/replacer tube tool No. T85T-7025-A nut and washer or equivalent.
33. Remove temporary spacer from countershaft, then install countershaft rear bearing. Tightening shaft locknuts without fully seating bearing can cause damage to output shaft threads.
34. Lock transmission into first and third gears. Install new output and countershaft locknuts hand tight. Torque output shaft locknut to 160-200 ft lbs and the countershaft locknut to 94-144 ft lbs. Always use new output and countershaft locknuts when assembling transmission.
35. Stake locknuts to bottom shaft groove using countershaft locknut staking tool No. T77J-7025-F or equivalent.
36. Apply sealant to oil passage retaining bolt. Position oil passage to transmission case and install retaining bolt. Torque to 6-8 ft lbs.
37. Install speedometer drive gear and steel ball to output shaft, then snap ring retaining speedometer drive gear to output shaft. Steel drive ball can be placed into any of the three detents. When installing speedometer drive gear, ensure replacement gear is same color as original.
38. Install oil funnel with tabs located in proper slots.
39. Remove any sealant residue from mating surfaces of transmission case and extension housing. Apply a 1/8 inch bead of sealant to transmission case. If extension housing bushing requires service, entire housing must be replaced.
40. Insert shift rail and selector finger assembly into rear hole of transmission case.
41. Guide shift rail through extension housing bushings, then position extension housing approximately 3/4 of the way to the transmission case.
42. Place offset lever and guide spring in extension housing, then move extension housing toward transmission case, guiding shift rail into offset lever and spring.
43. Seat extension housing assembly to transmission case, then install extension housing bolts and torque to 24-34 ft lbs. Ensure transmission rotates freely.
44. Align hole in offset lever to shift rail hole, then drive roll pin into holes.
45. Place synchronizers into neutral position. Ensure that shift forks on top cover assembly and shift rail selector finger are in neutral position. Apply grease to sealing gasket to retain position during assembly.
46. Check position of top cover gasket to ensure proper seating. Position top cover to transmission case, and carefully engage selector finger with shift forks, and shift forks with synchronizers.
47. Install top cover bolts and torque to 12-16 ft lbs. Apply sealant to rear two top cover retaining bolts prior to assembly.
48. Coat threads of drain plug with teflon sealant No. D8AZ-19554-A or equivalent. Install transmission drain plug sealing washer, then torque drain plug to 29-43 ft lbs.
49. If removed, install rear seal into extension housing using extension housing seal replacer tool No. T61L-7657-A or equivalent. Ensure oil seal hole faces downward.
50. After transmission is installed, add five ounces of friction modifier No. C8AZ-19B546-A, then fill transmission with Dexron II transmission fluid or equivalent. Apply pipe sealant to fill plug threads prior to installation.