Extension Housings - Overhaul

Extension Housings - Overhaul

Types A and B gearbox
1. Examine for damage to threads and machined faces.







NOTE: Types A and B gearbox extension housing shown.

2. Remove 3 screws and remove oil pump, remove and discard '0' ring.
3. Remove oil pick-up pipe and check for obstruction.
4. Drift out layshaft support bearing.
5. Remove and discard output shaft rear oil seal.
6. Drift out output shaft support bearing and oil pick up ring.
7. Unscrew reverse inhibitor shaft.
8. Remove reverse inhibitor cam and spring.
9. Remove reverse light switch and sealing washer, discard sealing washer.
10. Remove gate plate.
11. Check all components for wear and renew as necessary.

Type C gearbox - As for A and B Types and including the following:

12. Recover speedometer drive gear and spacer.
13. Check speedometer drive gear for wear and damage, renew if necessary.
14. Check speedometer pinion for wear and damage. Check that scrolling on shaft is clear; renew pinion and shaft if necessary.
15. Check slots in interlock spool for wear, renew interlock spool if necessary.

Type C and D gearboxes

CAUTION: The output shaft rear oil seal fitted to Type C and D extension housings is different to Types A and B. When levering out seal, take care not to damage the seal location surfaces.







NOTE: Type D gearbox extension shown.

1. Remove and discard output shaft oil seal.
2. Remove 3 screws and remove oil pump, remove and discard '0' ring.

Reassemble
1. Lubricate oil pump recess with gearbox oil.
2. Lubricate new '0' ring with gearbox oil and fit to oil pump.
3. Locate oil pump into extension housing ensuring that word 'TOP' on pump is towards top of housing.
4. Align fixing screw holes and tap pump lightly at edges until it is fully in housing, fit screws and tighten to 6 Nm (4.5 ft. lbs.).

CAUTION: Do not pull pump into housing by tightening screws.

5. Fit new output shaft support bearing.







6. Lubricate a new output shaft rear oil seal with gearbox oil and fit seal using tool LRT-37-014.
7. Fit new layshaft support bearing.
8. Fit new oil pick-up ring ensuring that tag is aligned with centre of drain slot.
9. Examine gate plate and renew if worn or damaged.
10. Fit gate plate, fit bolts and tighten to 15 Nm (11 ft. lbs.).
11. Fit reverse light switch and new sealing washer. Tighten to 24 Nm (17 ft. lbs.).
12. Apply Loctite 290 to threads of reverse inhibitor shaft, position shaft and fit reverse inhibitor cam and spring.
13. Tighten reverse inhibitor shaft.
14. Refit oil pick-up pipe, bend uppermost.