Author Topic: Clutch adjuster 3 speed box, part 29-3794/  (Read 153 times)

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Offline Kiwipom

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Clutch adjuster 3 speed box, part 29-3794/
« on: November 10, 2019, 05:12:43 am »
Hi, my first question, should the clutch adjuster “pin” 29-3794, inside the gearbox cap, have a ball bearing in its tip?

I ask as my bike has a part that looks identical to the one on this link: https://www.baxtercycle.com/product/29-3794/ and that has no ball bearing.

...but I found a loose ball bearing inside the box (luckily) after I re routed the cable, and caused the arm to slack right off. I need to somehow replace the ball bearing as otherwise the clutch arm on the box will hit the cable adjuster before moving the clutch.

I can’t see how the ball was held in place?

Offline Owen

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Re: Clutch adjuster 3 speed box, part 29-3794/
« Reply #1 on: November 10, 2019, 10:37:40 am »
The clutch operating spindle lug 66-3421 should have the ball in place that the clutch push rod thrust pin 29-3794 pushes against.
1940 C12 (350cc)
1945 C10 & C11
1953 C10 & C11
Anyone want a B20 in need of a lot of tlc

Online camman3

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Re: Clutch adjuster 3 speed box, part 29-3794/
« Reply #2 on: November 10, 2019, 03:22:27 pm »
Blessed things are always falling out....I believe somebody on here found FIVE ball bearings in their gearbox.
I thought the ball is supposed to be held in place by peened edge which has probably worn ....a bit of grease will hold it in place on assembly  :-\
Graham
1957 C12
In sunny (sometimes) Christchurch, Dorset, UK

Offline Kiwipom

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Re: Clutch adjuster 3 speed box, part 29-3794/
« Reply #3 on: November 10, 2019, 07:31:55 pm »
The clutch operating spindle lug 66-3421 should have the ball in place that the clutch push rod thrust pin 29-3794 pushes against.

Thanks, Just to sure, I guess the ball is just “loose” inside the lug thread then? I can (now) see the parts list describes the lug as “clutch operating spindle lug complete with ball” - but doesn’t show the ball on the diagram (unless I’m missing it). The ball bearing I found lying in the box is actually slightly too large to fit inside the lug, but I can fit a smaller one no problem.

Ive got an A10 and B31 and they have a different design, where the adjuster is bigger diameter and has the ball retained by the adjuster tip being peeled over, I guess because the balls DO fall out with the c11 design  >:(

Offline Kiwipom

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Re: Clutch adjuster 3 speed box, part 29-3794/
« Reply #4 on: November 10, 2019, 07:35:57 pm »
Blessed things are always falling out....I believe somebody on here found FIVE ball bearings in their gearbox.
I thought the ball is supposed to be held in place by peened edge which has probably worn ....a bit of grease will hold it in place on assembly  :-\
Graham

Thanks, the adjuster pin is quite small diameter, circa 1/4”, so the ball would have to be pretty small to fit in the tip? Do you mean the lug is peened over?

It’s a worry to have metal parts floating around that could jam between gears!

Offline timsdad

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Re: Clutch adjuster 3 speed box, part 29-3794/
« Reply #5 on: November 11, 2019, 06:56:45 am »
The adjuster arm has a socket in it that is larger than the ball so it can roll around in it very easily, Mr K. The lip of the socket is then peened over when new so the ball is retained loosely in place but is free to rattle around against the end of the push rod when there's clearance. The purpose of this is because the arm moves through a shallow arc when operated so has to slightly roll across the push rod end whilst pushing it forwards.

As Graham noted, a blob of thick grease holds it in place for assembly but then you have the danger of it falling out whenever the cable is disconnected after the grease is washed off by the oil splash. It's very common for lost balls to be found inside the gearbox but, in practice, I think it's unusual for them to find their way though to the gears from the chamber between the covers.


Ray
Just a motorcyclist.

Offline Kiwipom

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Re: Clutch adjuster 3 speed box, part 29-3794/
« Reply #6 on: November 12, 2019, 09:32:08 am »
The adjuster arm has a socket in it that is larger than the ball so it can roll around in it very easily, Mr K. The lip of the socket is then peened over when new so the ball is retained loosely in place but is free to rattle around against the end of the push rod when there's clearance. The purpose of this is because the arm moves through a shallow arc when operated so has to slightly roll across the push rod end whilst pushing it forwards.

As Graham noted, a blob of thick grease holds it in place for assembly but then you have the danger of it falling out whenever the cable is disconnected after the grease is washed off by the oil splash. It's very common for lost balls to be found inside the gearbox but, in practice, I think it's unusual for them to find their way though to the gears from the chamber between the covers.


Ray

Thanks it’s back together now with better clutch cable routing, I might get to test ride it tomorrow...for the first time ;D if that goes ok (engine has started but other than that it’s condition is unknown) then it’s not too far away from being ready for starting the re registration process, tho getting a working speedo on it will be a challenge (I got a chronometric with it, but it’s for a WD norton, not a bsa!)