Author Topic: gearbox clutch arm  (Read 782 times)

Offline edboy

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gearbox clutch arm
« on: 07.11. 2018 20:15 »
my gearbox clutch pivoting arm is heading west. chewing up the alloy casing as it goes. the greased rod is being pulled inwards requiring constant clutch adjustment. this caused a wear cycle and seems a bad design. anyone had a go at gearbox cover repairs or tried a modification?

Online trevinoz

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Re: gearbox clutch arm
« Reply #1 on: 07.11. 2018 20:17 »
Ream or drill the cover and fit a bronze bush.

Offline edboy

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Re: gearbox clutch arm
« Reply #2 on: 07.11. 2018 20:23 »
thanks for repy trev. have you done this? and is bronze the right material as the arm looks hardened.

Online KiwiGF

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Re: gearbox clutch arm
« Reply #3 on: 07.11. 2018 20:24 »
Ream or drill the cover and fit a bronze bush.

I second that, you may also need the arm ground round again, my engineer did this job but needed to put a lathe centre mark in the top (visible) part of the arm, not a biggie.
New Zealand

1956 A10 Golden Flash  (1st finished project)
1949 B31 rigid “400cc”  (2nd finished project)
1968 B44 Victor Special (3rd finished project)
2001 GL1800 Goldwing, well, the wife likes it
2009 KTM 990 Adventure, cos it’s 100% nuts

Online trevinoz

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Re: gearbox clutch arm
« Reply #4 on: 07.11. 2018 21:06 »
I have done a few.
Be careful drilling the cover as there is not much alloy around the hole inside.
I use leaded gunmetal bushes from a bearing supplier.
The first I did I drilled to suit the bush but later I machined the bush  o.d. smaller to lessen the chances of breaking through the alloy.

Offline Peter in Aus

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Re: gearbox clutch arm
« Reply #5 on: 07.11. 2018 23:45 »
I set mine up in the drill press to get it square and straight and drill it out using 1/2 drill and make a steel bush to fit, don't make it to tight just a firm push fit and use loctite. I have done 4 like this with no trouble.
Peter

Busselton West Australia
49 A7 longstroke
58 A10  SA

Offline edboy

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Re: gearbox clutch arm
« Reply #6 on: 08.11. 2018 18:38 »
 my inclination is towards a steel bush rather than bronze. i now have to find some bar and search for the buried lathe at the back of the garage.

Offline RDfella

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Re: gearbox clutch arm
« Reply #7 on: 14.11. 2018 19:09 »
Steel is likely to rust. May not be a problem internally if well greased, but will look bad outside. Bronze will last as long or longer (it is a bearing material)
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.