The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: coater87 on 08.01. 2017 06:27

Title: Gearbox cover clutch arm bushing
Post by: coater87 on 08.01. 2017 06:27
 I made new bushings for the kick-start and gear change levers. These were easy enough with the shop.

 The real problem is the clutch lever. The case hole is a bit sloppy. I fiddled around with a junk cover, and to get a bushing with any type of wall thickness really weakens the casting. Too thin of a bushing just makes insertion impossible.

 What are other people doing for this?
Title: Re: Gearbox cover clutch arm bushing
Post by: muskrat on 08.01. 2017 06:38
G'day Lee.
Howabout running a reamer through the hole to make it round then make a sleeve for the shaft.
Cheers
Title: Re: Gearbox cover clutch arm bushing
Post by: KiwiGF on 08.01. 2017 08:29
My engineering guy made a bush for the clutch lever on my bike, s/a gearbox, he first made the lever shaft round, he was very apologetic about having to make a centre mark on the lever top,  which is visible if you are eagle eyed  *whistle* ......needed to support the lever in the lathe when making it round.

Maybe he just made a relatively thin wall bush? I've not looked to see the wall thickness *dunno*



Title: Re: Gearbox cover clutch arm bushing
Post by: muskrat on 08.01. 2017 09:58
G'day KiwiGF.
Nice job, I wouldn't have noticed if you didn't alert us of the tiny dimple. Your lever appears to be at a bit of an obtuse angle. Another BSA cost cut in eliminating the threaded adjuster there which means your at the mercy of the inner cable length.
Cheers
Title: Re: Gearbox cover clutch arm bushing
Post by: orabanda on 08.01. 2017 10:12
Coater7,
It is a straight-forward job to drill the hole in the  cover oversize, then make a thin wall bush from brass, shrink it in, then drill the grease nipple hole through the side, and ream the bore of the bronze bush to size. The drilling should be done on a drill press (or mill, if available), with the cover on a jig or angle plate set up such that the original hole is at 90 degrees to the hole. You can make a mandrel out of mild steel round, to act as a guide when setting up.

Every cover I have seen, has required bushing.

Richard

Title: Re: Gearbox cover clutch arm bushing
Post by: BSA_54A10 on 08.01. 2017 10:28
Make the hole round the turn down some round shaft to fit in the hole.
A little visit with the welding torch, drill a new hole & job done for another 60 years.
Or if you are or know a good welder, build up the case or fill the old hole completely then make a new hole.
Title: Re: Gearbox cover clutch arm bushing
Post by: coater87 on 08.01. 2017 13:41
 OK,

 Looking at Kiwis picture, i am thinking this cover has been polished to death.

 Where you can see the land under his lever ball, mine has almost no meat left at all. I may be able to go out to 15/32 before I break through make things look bad. The lever shaft is in good shape, and measures 7/16.

 Maybe my best bet here is to make the best fitting sleeve I can for the current cover, and keep an eye out for one with more aluminum left.

 Lee
Title: Re: Gearbox cover clutch arm bushing
Post by: chaterlea25 on 08.01. 2017 18:40
Hi All,
I use old Triumph valve guides to make bushes for the casings  *eek*
They are 0.502(?) od so are a nice shrink fit into a 0.5in reamed casing hole
I usually find a better lever or buy a new one

Works for me ;)
John
Title: Re: Gearbox cover clutch arm bushing
Post by: ellis on 08.01. 2017 21:27
My clutch arm was very sloppy and not having a lathe to make a new bush I opted for a new stainless arm from Draganfly. Fitted the new arm and it has taken virtually all the play out so the arm was worn more then the bush. Job sorted.   *smiley4*
Title: Re: Gearbox cover clutch arm bushing
Post by: madsens on 08.01. 2017 21:33
Hi
I Had the same problem and also a ball adjuster that had been grinded totally down - ended up buying a secondhand gearbox cover from Draganfly, and lo and behold, it came with the lever as well and after disassembly, cleaning and greasing it was a total  perfect fit, no sloppiness - the ball adjuster I got from De Groot in NL
regards Joergen