Mainshaft

Fig. 1 Exploded View Of Transmission:

1. Partially assemble synchronizer components as follows:
a. Place a stop ring flat on bench, then the clutch sleeve and gear.
b. Place struts into slots and snap a strut spring into place with the tang inside one strut.
c. Turn assembly over and install second strut spring with a tang in a different strut.
2. Slide 2nd speed gear onto mainshaft with synchronizer cone facing toward rear against shoulder.
3. Slide 1st-2nd synchronizer with stop ring lugs indexed in slots onto mainshaft against second gear cone and secure with new snap ring. Slide next stop ring onto shaft and index lugs into clutch hub slots.
4. Slide 1st speed gear with synchronizer cone facing forward into position against clutch sleeve gear.
5. Install mainshaft bearing retaining ring, then the mainshaft rear bearing. Press bearing into place and install new snap ring to retain bearing.
6. Install partially assembled mainshaft into extension housing and compress bearing retaining ring so mainshaft ball bearing can move inward and bottom against thrust shoulder in extension housing. Release and seat ring in groove in the housing.
7. On except overdrive units:
a. Slide 3rd speed gear onto mainshaft with synchronizer cone facing forward, then the 3rd gear stop ring.
b. Install 3rd-4th synchronizer clutch gear assembly on mainshaft with shift fork slot facing rearward against 3rd speed gear.
c. Install retaining snap ring, then with grease position front stop ring over clutch gear, indexing ring lugs with shift struts.
8. On overdrive units:
a. Slide overdrive gear onto mainshaft with synchronizer cone facing forward, then the overdrive gear stop ring.
b. Install 3rd-overdrive synchronizer clutch gear assembly on mainshaft with shift fork slot facing rearward against overdrive gear.
c. Install retaining snap ring, then with grease, position front stop ring over clutch gear, indexing ring lugs with shift struts.
9. On all units, coat new extension housing to case gasket with grease, then place gasket on housing.
10. Slide reverse idler gear to center of the shaft, then move the 3rd-4th synchronizer sleeve or the 3rd-overdrive synchronizer forward.
11. On all except overdrive units, move drive pinion forward to provide maximum clearance for mainshaft pilot end.
12. On all units, slowly insert mainshaft assembly into case, tilting the shaft as necessary to clear idler and cluster gears. On all except overdrive units, engage the mainshaft with the pilot rollers in the drive pinion gear.
13. On except overdrive units:
a. Place 3rd-4th synchronizer sleeve in neutral position.
b. If all components are positioned properly the extension housing will bottom on the case without force. If not, check position of struts, pinion rollers and stop rings.
c. Install and torque extension housing attaching bolts to 50 ft. lbs.
d. Install drive pinion bearing retainer and gasket. Coat attaching bolt threads with a suitable sealing compound, then install and torque bolts to 30 ft. lbs.
14. On overdrive units:
a. Place 3rd-overdrive synchronizer sleeve in neutral position.
b. Rotate extension housing on mainshaft to expose countershaft rear and install one extension housing attaching bolt, holding housing in inverted position and preventing housing from moving rearward.
c. Install drive pinion and bearing assembly through front of case and into front bore. Install outer snap ring in bearing groove. Tap lightly into position with a mallet. If all components are positioned properly, the bearing outer snap ring will bottom onto case face without force. If not, check position of struts, pinion rollers and stop rings.
d. Turn transmission upside down while holding countershaft gear assembly to prevent damage.
e. Lower countershaft gear assembly into position with teeth meshed with drive pinion gear. Ensure thrust washers are positioned properly with the tangs aligned with case slots.
f. Start countershaft into bore at rear of case and push until approximately halfway into case, then install woodruff key. Push shaft forward until end is flush with case surface. Remove dummy shaft.
g. Properly align extension housing on case and install and torque extension housing attaching bolts to 50 ft. lbs.
h. Install drive pinion bearing retainer and gasket. Coat attaching bolt threads with a suitable sealing compound, then install and torque bolts to 30 ft. lbs.
i. Install new expansion plug in countershaft bore at front of case.