Disassembly
Disassembly involves pulling the transmission apart from the outside in:
• Remove the sprocket
• Remove the shaft bearings
• Remove the clutch pulleys
• Record the disposition of the shims
• Remove the inner clutch plates and yoke bar/bearing.
In my case removing the sprocket was quite a trial. Even though the sprocket itself was slightly free on the shaft, the woodruff key was a press fit in the key slot of the socket such that a large puller was necessary to hoik the sprocket off the shaft over the resistance of the key. I did try using the adjacent bearing plate for that purpose (as advised elsewhere in the forum) but only succeeded in bending the plate
. Applying sufficient force via a bearing puller eventually did the trick but it took some doing.
After I got it apart I took the liberty of grinding down the sides of the woodruff key slightly so that it would only require mild force to remove next time. I also noted that the woodruff key has embossed in it a pattern from the thread of the screw that holds the sprocket and disk chain guard washer in place. That means that if the woodruff key does need to be replaced (not highly likely) then it may be necessary to use a thread cutter to enable the bolt to go back into the shaft. So, don’t lose the original sprocket woodruff key.
The bearings have an unusual configuration in that their inner races are extended to provide for retaining grub screws. Removing the shaft bearings was a simple matter of loosening the grub screws and using a small puller to overcome the slight resistance, most from minor corrosion on the shaft. I did carefully note the distance of both bearings from their respective ends but ultimately it did not matter because both of the bearings get put back on to the shaft as far as they will go and are set once reinstalled.
With the sprocket now removable, it was returned to the shaft and used as both a mount and rotation preventer for getting the large nuts holding the outer clutch pulley bearings onto the shaft. The transmission was held (carefully) by the socket in a vice to make the whole assembly amenable to handling. This enabled the large clutch pulley bolts to be undone with a large shifter. These large nuts had also been secured with a medium strength thread locker.
Behind each of the clutch pulleys is one large washer and none-to-several smaller shims and the springs – the subject of much debate elsewhere in the forum. Note how many shims were installed in each side; in my case, 3 and none. Despite my expectations the springs were intact.
With the large outer clutch plates, washers, shims and springs removed it is a simple matter to slide the inner clutch plates and yoke bearing off the squared section of the shaft. Even though the fit of the cork-on-aluminium clutch surface is not particularly precise, it is probably a good practice to ensure that the clutch pulleys and inner plates remain identified as pairs for re-installation together.
With everything as removable as it should be it should only take 15 mins to disassemble the transmission.
