High Gear Machining for Circlip

Hello. Upon inspecting my high gear, which is perfect, I see there is no circlip groove outer or inner. So it must be a 750 unit. Is there any reason that my machinist couldn't cut a groove and I install at least an outer clip? Is that a reasonable assumption? Thank you.

robertv said:

Hello. Upon inspecting my high gear, which is perfect, I see there is no circlip groove outer or inner. So it must be a 750 unit. Is there any reason that my machinist couldn't cut a groove and I install at least an outer clip? Is that a reasonable assumption? Thank you.

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Are you seeing some reason to go to the trouble. I like the inner and outer circlip version but honestly, no circlip has worked for over 50 years!

To answer your question, yes, a good machinist could cut the groove(s) and you could replace the bushings (and probably have to have them honed).

Thank you for your reply. That is what I wanted to know. I am just getting to know Nortons and if it is a fairly rare occurrance for the bushings to move then I shall use this sleeve gear with no grooves. Again, thanks.

I grind the circlip groove into the sleeve gear, in the lathe, using a tool post mounted grinding spindle fitted with a small cutting disc from a dremel kit. Works a treat. I,ve had to do this on a few sleeve gears ranging from a 1956 ES2 to a late Mk2a.
If you do replace the bushings, DON'T hone them out. If they are tight on the mainshaft after fitting you need to ream them out. Honing is actually circular lapping using an abrasive stone. you do not want any particles of abrasive stone to get embedded in the bush. Reaming is a cutting process so no abrasive used.
Using bushings from RGM or AN i have had no problem with tight bushes.


Photo of circlip groove ground into sleeve gear

robertv said:

So it must be a 750 unit.

Click to expand...

No not necessarily 750 as the single circlip at the outer end wasn't fitted until the 850 Mk2/2A. The Mk3 type has two circlips.