Replacement gearbox questions K3

[muzikill]

As you know in my other threads i am in the process of replacing my k3 gearbox i have a few questions and hopefully i will get a few replies back saying all is normal!

Here are the pics to show what i am querying.


First thing is the replacement driveshaft i bought on the left isnt tapered at the top like the old one


Slight overlap on the driveshaft when its all fitted...


So i tried running it in neutral and these two dogs at the bottom of the driveshaft kept 'slightly' touching when turning it.


Here is it all fitted, i've put the arrows on the driveshaft because when you grasp it the whole shaft 'wiggles' slightly when fitted in the crankcase bearing. I don't think there is anything wrong tbh as the shaft end that fits in the bearing aint that long and i will probably find when the cases go together it'll be pretty solid. The bearing was inspected and 'tugged' at and didnt move a inch out of the ordinary.


Here it is in the upright position, when i 'turn' the gearbox the 'dogs' rubbing each other problem dissapeared!. Maybe its was just me being thick trying to test it flat!

I put the old gearbox, selector forks & selector barrell back in and all the above issues were still there so maybe i am looking for a problem when there isnt one!

I have used the selector forks and barrell from the replacement gearbox so they match, i noticed the selector forks had different part numbers from the 'old' one.

And lastly, some advice on how to turn the drive shaft and direction i turn the selector barrel to change the gears so i can test that the gearbox works before i put it all back together is appreciated!

[muzikill]

Update . . I think the drive shaft overlap is being caused by the new pushrod seal being driven in slighty too far i will consider removing it and re checking the alignment again. Another way is when the crank cases are put together it would align again

It is all good. You can't test shifting without engine been fully assembled, even than you have to spin shaft and shift in same time.

[yorkie_chris]

Yeah there's too much play in everything to test it without putting cases together, it will all knock together and feel like it has seized or something.

What's with the tapering thing in the first pic?

[muzikill]

Check out the teeth on the gear at the top of each shaft. The old shaft teeth are tapered the replacement is not

I can see that I was asking Zadar or YC.

[muzikill]

no probs it freaked me out when i noticed it points towards a design change / update i dont know if the taperless version proves it is pre k3 or not or wether its k4 onwards and an answer would be usefull

Taper makes no difference, both are tapered, one more than other. Probably just another run of parts. That part of gear is never touching anything.