T21 Layshaft Bearing Conversion.

[AndrewT21]

Hi,
As a new member let my introduce myself. I'm a recently retired petrolhead who has just got his teeth into the stalled rebuild of a 1958 T21. I did a lot of work on the bike a good while ago and then life got in the way!

The big problem I'm facing now is the gearbox - the original gears and shafts were badly corroded due to water entry and I was able to buy a really good second-hand set. But, the replacement set have the shorter layshaft and use the needle roller bearings - the originals use the phosphor bronze bushes.

I've looked at parts books and think I know the parts I need for the conversion - but has anyone here done it? If so it would be great to details of what they did.

Thanks,

Andrew.
ps - if this has been covered already please accept my apologies but I didn't find it.

 

[Rocky]

Hello and welcome to TT from the east coast of Canada
I can't answer your question, but I'm sure Grandpaul or Rudie might be able to help. Give them time to catch up.

 

[grandpaul]

Hi,
As a new member let my introduce myself. I'm a recently retired petrolhead who has just got his teeth into the stalled rebuild of a 1958 T21. I did a lot of work on the bike a good while ago and then life got in the way!

The big problem I'm facing now is the gearbox - the original gears and shafts were badly corroded due to water entry and I was able to buy a really good second-hand set. But, the replacement set have the shorter layshaft and use the needle roller bearings - the originals use the phosphor bronze bushes.

I've looked at parts books and think I know the parts I need for the conversion - but has anyone here done it? If so it would be great to details of what they did.

Thanks,

Andrew.
ps - if this has been covered already please accept my apologies but I didn't find it.

Howdy, Andrew.

It may have been covered, try a detailed search.

Personally I can't answer that without referring to shop manuals which I currently don't have at hand quickly. I've never done that conversion myself.

@Rudie should be along presently to lend a hand...

 

[Greyfell]

Here is a thread from one of Gandpaul's projects, that sounds close to what you're asking about: TRITON! ...at last...

 

[grandpaul]

Here is a thread from one of Gandpaul's projects, that sounds close to what you're asking about: TRITON! ...at last...

Actually, that one is for converting the late 650 4-speed unit trans to a 5-speed. OP has a very early unit 500. Different kettle of fish, I think...

 

[speedrattle]

what are the diameters of the bush, bearing and layshaft? the bearing may just press in, oe the hole might need to be reamed. it was common enough to do that it is probably not difficult