Topic: 400F Gear Spindle Question

[jakec]

I'm rebuilding my engine using most of the lower end from a donor engine. When i bought the engine (already partly taken down, in boxes) the PO told me that the shift shaft (part shown in photos) was "bad" and he had a new on in the box of parts. The original was removed from the engine already.

The original one is the one on the right. The "new" one is on the left. It has some corrosion on the shaft.







The thing is, I can't tell any difference between them, and I'm trying to figure out which one to use in the rebuild.

[bryanj]

Its usually the spline for the pedal that wears due to pedal not being kept tight

[Flyin900]

Use the new one as Bryan said the splined spindle is the wear point on most shafts. Get some 0000 steel wool and WD40 soaked into the wool and clean up the shaft. If you don't have steel wool then how about 2000 grit sandpaper with the WD40. Don't be aggressive with either product, you just want to clean up the shaft lightly from any grungy build up to get it clean.

[jakec]

Looking at the splines, they are about the same. They both have a little corrosion to the splines that would need to be cleaned up, but I can test them before installing in the engine. Is there anything else to consider? I guess I can always change thisnoart later if I need to.

[jakec]

so I made some good progress on my engine tonight, I mated the cases up and was chugging along pretty nice until I got a bit stuck. I cleaned up the shaft of the supposedly new spindle, and installed it with the rest of the gear change mechanism parts. I attached photos below of what it looks like. I assembled the engine with the selector shaft in neutral. This is confirmed by the brass neutral switch nub being visible.

I installed all the parts, and although the orientation of my "star" piece is different than in the video I'm watching, it goes together ok. Then when I'm tightening the retainer plate down, rotating CW, the gears start shifting up from the rotation force. No worries, I finish tightening, and then move the switchgear by hand, 6 times, back down to where it started. But then after that, it wouldn't shift again. I attached the gearshift foot lever and tested it, and it wouldn't budge either way. I reinstalled all the parts maybe three times with the same results. So I stopped for the night. Didn't want to put the clutch on until it was in the frame anyways.

[bryanj]

Both shafts need to turn to get the gears easy

[jakec]

Can you confirm that I have everything installed ok? I know you work on 500's but I assume this mechanism is the same cause I have seen a 500 transmission in photos.

Are you saying that I just need the gear shafts spinning a bit to make the shift easier? Because I'm aware of how this can be the case on a running bike, so I tried this but it didn't make a difference.

[bryanj]

Having built losts of 500/550 both shafts need to turn at same time to get easy change. If you really cant get the mechanism to turn the drum when you are spinning shafts something is assembled wrong and for me to com and look would be a bit expensive as i am in UK!!!

[jakec]

Haha true, not sure you want to come here now anyways.

Well Like I said I was able to shift up when tightening the retaining screw, it clicked up really nicely. Then i was able to click it down by hand, also nice smooth clicks. But once I got it back down to neutral it wouldn't move anymore. Maybe if I rotated the gear selector shaft with a wrench again.

[bryanj]

Possibly, spin the mainshaft whislt doing it, can you get 1st (other side of neutral)

[jakec]

Neutral should be the flat part/point of the star piece, where the left wheel is resting? Correct?and rotatin CW would be shifting up? If so I don't think I ever shifted into first. only CW all the way to 6, then back down.

I did confirm that I have my shift forks in correctly, R,C,L and oriented the only way possible for the shaft to be in neutral.