Gearbox Overhaul and The Mystery O Ring

Hello All,
I finally completed an overhaul of my MKIII gearbox. New bushings and bearings and a
thorough inspection of all the mechanical bits. It worked really well, but on occasion I would get false neutrals , especially when downshifting. After a lot of head scratching
and consulting haruspices concerning the hairspring--I determined that the hairspring was probably fine. So I took one last look at the exploded diagramme of the outer cover.
There is an O-ring that goes on the shiter shaft behind the ratchet plate. I had omitted this part. It looks like its purpose is to maintain a little clearance between the ratchet plate and the hairspring. Now the gearbox is much more consistent and I believe the issue is solved. If anyone has had a similar epiphany, I would love to hear about it.
Very Sincerely,
Kara

Dunno about that. But I do know the importance of a roller layshaft bearing. Frozen and Hot.

Tinkerbell said:

There is an O-ring that goes on the shiter shaft behind the ratchet plate. I had omitted this part. It looks like its purpose is to maintain a little clearance between the ratchet plate and the hairspring. Now the gearbox is much more consistent and I believe the issue is solved. If anyone has had a similar epiphany, I would love to hear about it.

Click to expand...

The O-ring is a Mk3 parts book error!

It's not required for the Mk3 gearbox as the O-ring is the gear indicator spindle seal on the RH shift gearbox (Item 6).
https://andover-norton.co.uk/en/shop-drawing/209/gearbox-inner-cover

The Mk3 parts book amendments list inside the front cover states: "Page No.7 (Group 7) Item No. 19, 04-0079, Deleted - Not Required".

Edit:
https://www.accessnorton.com/NortonCommando/mkiii-trans-rebuild-questions.17124/
https://www.accessnorton.com/NortonCommando/where-does-this-o-ring-fit-in-tranny.21324/