My gearbox revision thread

[goldnsx]

Hi Kaz

Thanks for your valuable reply.

Release bearing
So I'm going to change all the parts around the release bearing: fork, guide, hunger, spring...

Mainshaft
I'm going to install two new bearings on the mainshaft and put it in the gearbox. Cleaning the contact surface of the two case halfes thoroughly. 45 Nm. With only one shim (standard 1.00) I'm going to measure the clearance. As I expect it to be higher than the targeted 0.14-0.21 mm, so the resulting clearance will be determined. Also, as I don't have the Honda tool I won't be not able to use that much force like the tool would allow, so I'm aiming for the lower half of the deviation (0.14-0.17). I've done some combinations of pairs of shims which allows me to order just 4 additional shims and still being able to get any clearance from 1.00 to 1.40 mm (for example) with 0.05 steps in between. For 1.05 I'd be using 0.50 and 0.55 for example (easier to install too).
I know that I have to do it again as soon as the new parts (new hub and gear for 5th) are installed but I don't think the clearance will be way off then. I just try to avoid to place a second order with weeks to wait again...

Oxidation on the fixing bolts
I didn't see any oxidation. The screws came out by hand without headaches. For breaking them loose most of them were pretty stiff but not overtorqued. I'm going to use less torque on them I guess (well, the one stated in the SM) and use a calibrated torque wrench for sure. I always use ceramic paste as an adhesive. You just have to make sure that you don't torque it too much as the resistance of the threads is lower with ceramic paste, so the resulting torque is maybe 10% higher than intended. Worked good in the past but will check for oxidation again.
The threads of one screw at the rear engine mount were damaged by a complete idiot who must have used air tools in the past. The threads can be repaired I think and I'm going to test if the threads can take 105 Nm or better reduce the torque a little bit.

In this time-consuming project I'll tend to replace more parts than actually needed. For example, the 2nd gear synchro was perfectly good, no need to replace it until I ruined the new part. If you can change a part within an hour I'll have a slightly different approach.