[Gerinemo]

Gearbox / Transmission advice needed
Well Looks like I have done it now
I decided to replace the gearbox / transmission due to the damaged output shaft

I got a secondhand gearbox on ebay and the output shaft seems fine on it
I removed the old gearbox and installed the replacement one complete
Started the bike and no funny noises or smoke
put it in to first gear which worked fine
Tried second which was also good ( Happy days or so I thought )
Tried third and although there was a little clunk like it going in to gear there was no drive to the wheel
Tried 4th and all I got was a grating / grinding noise so I left it there for the day as i was tired

This morning I tried it again same thing so I thought maybe the shift rod needed a little adjustment and I spent quite a while adjusting it back and forward with no success :-(
No Matter what I did it just will not go in to any gear after 2
Thinking the replacement box was duff I took it back out
When it was out I noticed that the Locating dowels were still in the old box I had forgotten to swap them over and although I was skeptical that the dowels would make any difference I put the box back in with the dowels

Needless to say it made no difference :-(
So I took the box out again getting quicker at it now

I swapped over the good output shaft in to the old box and reinstalled and the blasted thing is the same with the old box wont go past 3rd gear
The old box was working ok other than the shaft damage so I'm thinking it must be me doing something wrong on installation as both boxes are exhibiting the exact same symptoms

Any gearbox guru's out there can point me in the right direction ?
Or any input at all is welcome at this point
I did not dismantle the selector I just removed and reinstalled it while replacing the gearbox

 

[jdrocks]

you may have done this already...take a look at the parts schematic to make sure you have all the transmission parts installed in the proper position, then reference the service manual.

i haven't been into this transmission myself, but they're reported to be foolproof by those that have done the remove/replace.

 

[Gerinemo]

Howdy JD thanks for the reply

Yeah I also had the old and new ( to me ) gearboxes side by side to compare and checked the manual
And all looks to be in the right order

Gear position has been set to neutral & both shafts rotate freely
Gearbox is then installed and rechecked that the shafts rotate freely in neutral
the neutral switch and selector are then installed and movement of both shafts checked again
Clutch and covers reinstalled
Oil added start the engine
first and second gear go in and Now third appears to be working but when I try to up shift to 4th although the lever comes up there is no clunk or click nothing happens
If I down shift it goes back to 2nd and then neutral

This is being tested with the Bike on the paddock stand I have not tried riding it on the road
Last week while cleaning the chain i was able to cycle through the gears with the bike on the stand to sling the oil off the chain before cleaning the tyre

 

[Gerinemo]

Been out tinkering with the bike

Took it off the paddock stand to try bring it for a run see would something slip in to place

I was checking the adjustment of the clutch by putting it in to first gear pulling in the clutch in and pushing the bike to see if the clutch was releasing and to my surprise it did not

The clutch lever and the clutch actuating arm on the clutch cover seem to be operating normally and I had oiled the cable and the cable is about a year old and moves freely and seems to be in good condition

I can feel resistance against the spring but it was like it was not doing anything the drive still seemed to be engaged

So I started to adjust the clutch more to try get it to the point where the drive to the wheel was disengaged

several turns later the back wheel started to turn while pushing in gear but there was no drive to the wheel when in gear & the clutch was released with the engine running

In order to get drive to the wheel I had to slacken off the adjustment but then pulling the clutch in while in gear did not appear to to release the drive to the wheel



Sorry about the long posts but this is doing my head in



Could this be why it wont go in to gear above third and not a gearbox problem at all?

Or is that wishful thinking

J

 

[Gerinemo]

The issue was definitely the replacement gearbox as with the clutch and basket removed the drum would not rotate past 3rd gear no matter what

I removed the box again ( getting to be an expert at it now ) and reinstalled the old box and other than the original damaged splines it is working Ok cycles through the gears by spinning the drive shaft by hand while turning the drum

I have buttoned it back up & refilled the oil

Started it up and runs and goes through the gears on the paddock stand

 

[JT in GA]

Thanks for sharing ... hope you are finished with this tale of woe and can put some miles on the bike without trouble !

 

[Gerinemo]

Hopefully
Shifting seems a lot smoother after all the messing
Got out for a little 20KM spin to try it out
I did give it some Castrol 10W40 FS though

 

[jdrocks]

i don't know what happened there, it should be a trouble free direct swap. a friend was one of many who have swapped in the same trans, worked perfectly.

 

[Gerinemo]

Murphys Law
If something can go wrong it will
Unfortunately for me it was not having any of it
The only thing I could see was that there was a little ding on the shift drum so maybe it got dropped somewhere along the way