Identify a Gear

[Aussie Bill B]

Sorting out some boxes of bits and I would like to identify this first motion/input gear.

Input gear mainshaft end.jpg

It is the same length as other 3 synchro inputs; 20 teeth, B form; letter "G" stamped into mainshaft end.
Have researched the Mk1 Performance Conversions tables and there are only a few 20 tooth gears. But there are no stamped part numbers to narrow it down.
Would appreciate any suggestions.

[Spider]

Are you able to ID if it's an A or B Form ?

[Andrew1967]

20 teeth normally denotes a Cooper input gear on a 3 synchro box.

I think (but could be wrong) the needle bearing is pressed in on an A type gear but floating on a B.

Simon (251ENG) might be able to shed some light

[OGW 1082]

Hi Andrew,
From what I have here that is correct.
I've 2 mk 1 S ones with G stamped in them and 2 'A ' forms with pressed in needle rollers both with 19.5 teeth.
Glen

[Andrew1967]

That does confirm my thoughts Glen, and also that my memory isn't as bad as the missus makes out

Maybe I only remember important things though

As Simon would confirm, Mini gearboxes are a nightmare regarding the sheer number of different gears that were available - crazy.

[Aussie Bill B]

Are you able to ID if it's an A or B Form ?

I have set the gear into a 22G1100 cluster gear and they lie parallel to each other so assume it is a B form.

[Andrew1967]

All non Cooper 3 synchro input shafts are 19 teeth, that applies to cone, A & B type gears.

[Aussie Bill B]

20 teeth normally denotes a Cooper input gear on a 3 synchro box.

I think (but could be wrong) the needle bearing is pressed in on an A type gear but floating on a B.

Simon (251ENG) might be able to shed some light

Andrew, when you say the bearing was pressed into the gear on an A form, was that as supplied as a spare part? Are there any tell-tale signs of the pressed-in bearing having been removed? Like a slightly different diameter...

[Andrew1967]

I'm not entirely sure on that Bill, I think the bearing is certainly replaceable.

The parts manual shows 88G409 as being common to all input shafts but the later ones are needle roller type, like the laygear style bearings. The pressed ones are (obviously) a caged needle roller type.

I have several NOS standard input shafts here, I'll have a look.

Simon N. is definitely the man for this question ...

[251 ENG]

If its 20T and B form must be a first motion to suit close ratio kit for 22G 232 / 22G 1100 laygear

[Aussie Bill B]

Thanks to all who contributed to an answer.
I don't remember buying this gear but I must have bought it for my 1966 Aust'n built S, which is now back on the road and running well. I used the original 22G333 box but am aware that these things will not be serviceable at some future point.