Mainshaft

DISASSEMBLE
1. Scribe alignment mark on third-fourth synchronizer hub and sleeve for reference during assembly, then remove snap ring and remove third-fourth synchronizer assembly from mainshaft.





2. Slide third gear off mainshaft, then remove snap ring from second gear and remove tabbed thrust washer, second gear and blocker ring from mainshaft.

3. Remove first gear thrust washer and roll pin from mainshaft, then remove first gear and blocker ring from mainshaft.

4. Scribe alignment mark on first-second gear synchronizer hub and sleeve for reference during assembly, then remove synchronizer springs and keys from first-second sleeve and remove sleeve from shaft.

NOTE: The first-second hub and mainshaft are assembled as a unit and no attempt must be made to separate them.

5. Remove loading tool, roller bearings, spacers, and thrust washers from the countershaft gear.


ASSEMBLE
1. Coat mainshaft and gear bores with transmission lubricant, then install first-second synchronizer sleeve on mainshaft, aligning marks made during disassembly.





2. Install synchronizer keys and springs into the first-second synchronizer sleeve. Engage tang end of springs into same synchronizer key, but position open ends of springs so that they face away from each other.

3. Place blocking ring on first gear and install gear and ring on mainshaft.

NOTE: Ensure that synchronizer keys engage notches in first gear blocking ring.

4. Install first gear roll pin in mainshaft, then place blocking ring on second gear and install gear and ring on mainshaft, ensuring synchronizer keys engage notches in second gear blocking ring.

5. Install second gear thrust washer and snap ring, ensuring that thrust washer tab is engaged in mainshaft notch.

6. Check second gear end play using a feeler gage. End play should be 0.004-0.014 inch. If end play exceeds 0.014 inch, replace thrust washer and snap ring and inspect synchronizer hub for excessive wear.

7. Place blocking ring on third gear and install gear and ring on mainshaft, then install third-fourth synchronizer sleeve on hub, aligning marks made during disassembly.

8. Install synchronizer keys and springs in third-fourth synchronizer sleeve. Engage tang end of each spring in same key, but position open ends of springs so that they face away from each other.

9. Install third-fourth synchronizer assembly on mainshaft with machined groove in hub facing forward, then install snap ring on mainshaft, ensuring that synchronizer keys are engaged in notches in third gear blocker ring.

10. Measure third-fourth synchronizer end play following procedure in step No. 6 above.

11. Install Tool J-26624, or equivalent, into countershaft gear, then, using a suitable lightweight grease, lubricate roller bearings and install into bores at front and rear of countershaft gear. Install roller bearing retainers on Tool J-26624.