Norton AMC gearbox 4th gear bushes

B+Bogus said:

L.A.B. said:

did you actually mean the inner face of the bush?

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Yes!

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OK, although this does however raise the question of bush end-wear (perhaps not directly attributable to the layshaft) which is going to result in increased layshaft end-float. Where what may be considered "excessive" end float is encountered, it may be prudent to replace the K/S shaft bush before attempting to shim the layshaft.

Again, as far as I know, there is no known installed depth dimension for the lay-K/S bush-or whether it really must be installed 'fully home'-or not, as not pressing the bush fully home would be another way of reducing end-float.

Just for reference on this gearbox under siege.
First gear layshaft, slight very slight wear on gear teeth, no discernible width wear in the gear steel at bushing.
A straight edge laid across gear....I cannot get a .001 feeler to go under.
measures about .506" height here to compare to the kick start shaft recessed bushing at .484".
overall width of this first gear on layshaft is about .740"
inside this gear you can see the teeth that the kick starter pawl engages....the teeth are about 0.330" wide

A little wear on the insert bushing in this kick start shaft indicated by the shiny ridge on the ID portion.
This is about .002" ridge.
This ridge is formed by the first gear bushing being tapered both outside (for ease of install in the gear) and inside (for ease of install onto shaft). see above photo.
I am not sure what is important about any of this info. It is specific to my gearbox......but I am trying to determine best placement of any shimming.....and moving just the kick start shaft to the inside does not seem best to me right now.

One of my big concerns was moving this kick start shaft further inward , away from full engage with the pawl cam that disengages the kick start , I believe called axle stop.
Examination this pawl in this picture shows a .390" wear pattern for kick starting engage.
The first gear only has .330" available to wear this pattern.
So this may indicate and existing gearbox layshaft float/endplay of .060"
It appears the disengage cam or stop is currently marring a .124" pattern.......I feel that reducing this to .060" (with shimming at .060" for new roller bearing with advised shim location) is not a good thing.

I was able to press off the layshaft 4th gear and what I had not noticed, prior to this removal, was the slot machined in the gear 040284 radius as shown.
The slot and the raised area were positioned to the inside.
I have not seen this slot mentioned before, but I thought I had read the raised area on this gear was to be positioned toward the bearing (opposite of what I found).
What direction should this 040284 face on the layshaft? and where is this addressed?
thanks


I found the "flange" mention in Mick Hemmings article about disassembly of the gearbox.
Maybe this slot was a later gear version to allow more lube for often failed layshaft ball bearing?
There is a "5" stamped on this "flanged " side of the gear.

Hi , about the "5" on your 4th gear layshaft gear all i can say is that some are stamped with a "6" and are not of the same OD and so must be paired with the appropriate sleeve gear ........I had asked before when building gearboxes from various parts and noticed that !! but never seen that groove ??