Removal
Note: Prior to removal, mark, or make a note of the relative positions of each selector fork in the selector drum.
1. Remove the engine from the frame as described on page 10.2.
2. Separate the lower crankcase from the upper as described on page 5.5.
3. Remove the output shaft from the crankcase.
4. Remove the "C" clip from the selector shaft.
![](https://motoinstruction.ru/img/triumph/7/114266.jpg)
1. Selector shaft; 2. "C" clip
5. Insert an M6 bolt, hand tight only, into the thread at the front end of the selector shaft.
6. Pulling on the inserted bolt, ease the selector shaft out from the crankcase, collecting each selector fork as the exiting shaft releases them.
![](https://motoinstruction.ru/img/triumph/7/114267.jpg)
1. Selector shaft; 2. Bolt; 3. Selector forks
7. Remove the input shaft as described on page 8.12.
8. Remove the bolt securing the gear change actuator arm to the gear change shaft.
![](https://motoinstruction.ru/img/triumph/7/114268.jpg)
1. Gear change actuator arm; 2. Bolt
Note: Removal of the gear change shaft will detach the gear change actuator arm as the shaft slides out. Collect the actuator from inside the crankcase as soon as it is released. In addition, the detent spring will also become detached from the spring abutment bolt.
9. Slide the gear change shaft out of the crankcase, collecting the gear change actuator arm and detent spring at the same time.
![](https://motoinstruction.ru/img/triumph/7/114269.jpg)
1. Gear change shaft; 2. Gear change actuator arm; 3. Detent arm
10. Insert a soft-faced implement through the selector drum to prevent it from turning, and then undo the screw securing the detent wheel to the selector drum.
![](https://motoinstruction.ru/img/triumph/7/114270.jpg)
1. Selector drum; 2. Detent wheel
11. Release the small screw securing the selector drum, bearing and keeper plate to the crankcase.
![](https://motoinstruction.ru/img/triumph/7/114271.jpg)
1. Selector drum bearing; 2. Screw; 3. Keeper plate
12. Pull/push the selector drum out and in to dislodge the bearing, then remove the drum from the crankcase.
13. To remove the actuator shaft, slide it inwards and recover it from inside the crankcase.
![](https://motoinstruction.ru/img/triumph/7/114272.jpg)
1. Actuator shaft
Note: It is not normally necessary to remove the inner selector drum bearing, though it is possible to do so by drifting from behind its recess in the crankcase.
14. If necessary, remove the spring abutment bolt.
Inspection
1. Inspect all springs for over-extension (i.e. abnormal gaps between coils). Replace as necessary.
2. Inspect all seals for damage and distortion. Renew as necessary.
3. Check the selector forks and selector grooves for wear beyond the service limits. Renew components as necessary.
Item | Standard | Service Limit |
Selector fork thickness | 5.90-6.00 mm | 5.80 mm |
Selector groove width | 6.05-6.15 mm | 6.30 mm |
Fork to groove clearance | 0.05-0.25 mm | 0.50 mm |
Installation
1. Refit the actuator shaft; ensuring it is pushed fully home in the crankcase.
2. Locate the selector drum to the crankcase and engage it in the inner bearing.
![](https://motoinstruction.ru/img/triumph/7/114273.jpg)
1. Inner bearing; 2. Selector drum
3. Fit the selector drum outer bearing, bearing keeper plate and retain the plate using a new screw. Tighten the screw to 12 Nm.
4. Apply Loctite 1305 to the threads of the spring abutment bolt (if removed). Fit and tighten it to 23 Nm.
5. Position the detent wheel to the selector drum, engaging the pin on the drum with the corresponding recess in the rear of the wheel.
![](https://motoinstruction.ru/img/triumph/7/114274.jpg)
1. Detent wheel; 2. Selector Drum; 3. Pin; 4. Recess
6. Fit a new screw to the detent wheel, prevent the drum from turning using a soft-faced tool, then tighten the screw to 12 Nm.
7. Slide the detent arm and spring onto the gear change shaft, with the spring eye end of the detent arm entering the shaft first.
![](https://motoinstruction.ru/img/triumph/7/114275.jpg)
1. Detent arm; 2. Spring eye; 3. Shaft
8. Position the assembly to the crankcase and part engage it in its hole.
9. Locate and hold the ball-end of the gear change actuator arm in the actuator.
10. Feed the gear change shaft through the crankcase, engaging it in the actuator arm and also attaching the free end of the detent arm spring over the spring abutment bolt. Ensure that the gear change return spring also engages over the spring abutment bolt.
![](https://motoinstruction.ru/img/triumph/7/114276.jpg)
1. Detent arm spring; 2. Spring abutment bolt; 3. Gear change return spring
11. Fit a new bolt to the gear change actuator and tighten it to 28 Nm.
Note: If a new bolt cannot be sourced, clean the threads of the old bolt and apply a spot of three-bond 1305 to the threads before fitting it.
12. Refit the input shaft as described on page 8.13.
Note: Selector forks are marked A, В and C. The marking letters always face the clutch end of the input shaft.
13. Place the transmission in neutral. The transmission is in neutral when the wheel of the detent arm rests in a tooth on the detent wheel that has a V-shaped cut-out.
![](https://motoinstruction.ru/img/triumph/7/114277.jpg)
1. V-shaped cutout; 2. Detent arm
14. Partially insert the selector shaft into the crankcase.
15. Position and support the selector forks in the selector drum as noted or marked prior to removal.
![](https://motoinstruction.ru/img/triumph/7/114278.jpg)
1. Selector forks; 2. Selector drum; 3. Selector shaft
16. Feed the selector shaft through the selector forks and secure it with a new "O" clip.
17. Assemble the crankcases as described on page 5.7.
18. Refit the engine as described on page 10.5.