Can't select gears

Hey guys, I am at the end of an unsuccessful weekend of work on my Featherbed project - I wonder if you can help me out.

As part of my build, I am fitting a Bob Newby Belt Drive and Clutch.
This weekend was the time to fit everything, and it went together perfectly.

However, with the clutch centre nut snugged up, I cannot select any gears.
When I loosen the nut off, I can select all the gears again.

The belt is aligned perfectly with the engine pulley, and tensioned right (90 degrees of twist on the belt)
The spacer behind the clutch baskets stops any rubbing on the primary case.

I've not yet fully assembled - I haven't put the clutch plates, pressure plate and pushrod on, so we know these are not causing an issue.

After a lot of pondering, we just can't work out what the problem is.

Any ideas would be really helpful, as I'm tearing my hair out here!

Thanks!

Sound similar to what I call my 'blank staring british iron stumper'.
Offering my guess now so I don't have to think about it trying to sleep after a weekend long straining. Maybe the main shaft nut on TS is loose and center nuts makes shaft shift to bind for no shifts? Ball fell out of the cable end lever? Belt tension of course should be set so fairly easy to twist full 90' cold. Locating clutch circlip bowed over? Maybe others returning to work stations Monday can offer more insights.

Yes, the ball was one of the things I checked.

Initially, it felt like a jammed gearshift pawl, ratchet plate or quadrant so I actually thought it was a gearbox issue to start with, so started stripping it down.

After a couple of hours of digging, disassembly, reassembly and replacing the gaskets again (grrrr) I confirmed there was nothing at all wrong with the gearbox.
Everything seems good that side.

It was during the reassembly of the gearbox that we noticed that the issue was being caused from the clutch side.

You have the CIRCLIP as well as the spacer behind the clutch, yes? Item 55 here: http://www.oldbritts.com/nor_comm_71_8.html

Yes - there was quite a substantial spacer that goes between the nut (item 56) in the pic and the clutch basket.

This spacer steps the basket out (bringing the two pullies perfectly in line) and stops the basket from rubbing on the primary case.

My guess is that is the equivalent to the circlip you mention?

gtiller said:

Yes - there was quite a substantial spacer that goes between the nut (item 56) in the pic and the clutch basket.

This spacer steps the basket out (bringing the two pullies perfectly in line) and stops the basket from rubbing on the primary case.

My guess is that is the equivalent to the circlip you mention?

Click to expand...

In CONJUNCTION with the circlip. Without it, just jammed against the sleeve gear, causing the lockup.

It sounds like concours has located your problem.
I got some from my local CBC bearing shop.
They call them "snap rings" to differentiate them from circlips which have the eyes for circlip pliers. You can't use that type of circlip in this instance.
As this snap rings bears all the load when the nut is tightened, I took the advice of other forum members and reduced the tightening torque to 40 ft-lb instead of the specified 70.

Martin

Awesome - thanks for this heads up!

Seems like the previous owner didn't think this part was important, as it wasn't fitted - but then again, neither was the lock washer. :roll:

I had spotted the missing lock washer, but not the circlip.
As this is my first Norton, I don't know all the parts inside out yet (although, I'm rapidly learning)

I have ordered the offending article from Andover, and will let you know what happens when it arrives!
Thanks for the recommendation on the torque - I'll be sure to follow that too.

Cheers!

gtiller said:

Awesome - thanks for this heads up!

Seems like the previous owner didn't think this part was important, as it wasn't fitted - but then again, neither was the lock washer. :roll:

I had spotted the missing lock washer, but not the circlip.
As this is my first Norton, I don't know all the parts inside out yet (although, I'm rapidly learning)

I have ordered the offending article from Andover, and will let you know what happens when it arrives!
Thanks for the recommendation on the torque - I'll be sure to follow that too.

Cheers!

Click to expand...

YW

Next time order three... one to lose, one to bend and one to run, lol