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Bending Clutch Levers
#1
Hi,

I've been having all sorts of issues with setting my clutch after I fitted a different clutch plate which had been repaired by inserting pegs into the worn part of the toggle slots.

Essentially the repair pegs were too proud of the slot bottom so I cut these back to achieve enough clutch engagement but, despite being very careful, I have ended up with the toggles being different heights and this is causing clutch vibration.

Ideally I should shorten the repair pegs a bit more adjusting the amount removed to get the toggles all the same height but this would be difficult without removing the posts and to do this I'd have to remove the clutch lining.   In addition I don't know how the repair pegs are retained and I'm a bit concerned they may simply be headed which would mean taking any more off the top could make them vulnerable to pushing through.

The easiest solution would seem to be to bend the toggles as mentioned in a number of articles but can this be done cold as a friend suggested and is it OK with the new toggle arms I got from Seven Workshop?   Also how hard is it to control the amount you're bending it by as the final result needs to be quite accurate.

John.
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#2
Bending them cold is something you must not do. You may break them or distort the pivot holes.
Heat makes the job really easy - cherry red in the centre part.
Do let them cool naturally.
Adjusting the levers in this way is the best way to set up your clutch.
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#3
All the repair pegs I have seen were screwed in from behind until the fingers were level and then the excess ground off flush. Various methods of preventing the pegs from subsequent movement  were, center punch, soft solder, locktite. If your fingers are new and still identical, and your pivot pins in the posts are new I would  review your repair peg heights rather than bending.
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#4
(30-06-2020, 01:12 AM)squeak Wrote: All the repair pegs I have seen were screwed in from behind until the fingers were level and then the excess ground off flush. Various methods of preventing the pegs from subsequent movement  were, center punch, soft solder, locktite. If your fingers are new and still identical, and your pivot pins in the posts are new I would  review your repair peg heights rather than bending.

This has to be the way to go, explore this fully first -from an engineering perspective, if you have all new fingers, they are identical, the fault is else where . it'd be far easier to control material removal from the peg than to control a bend. Getting the bend wrong means new fingers again . getting the pin wrong just means screwing a bit more through

(30-06-2020, 11:41 AM)Tim Watkins Wrote:
(30-06-2020, 01:12 AM)squeak Wrote: All the repair pegs I have seen were screwed in from behind until the fingers were level and then the excess ground off flush. Various methods of preventing the pegs from subsequent movement  were, center punch, soft solder, locktite. If your fingers are new and still identical, and your pivot pins in the posts are new I would  review your repair peg heights rather than bending.

This has to be the way to go, explore this fully first -from an engineering perspective, if you have all new fingers, they are identical, the fault is else where . it'd be far easier to control material removal from the peg than to control a bend. Getting the bend wrong means new fingers again . getting the pin wrong just means screwing a bit more through

the use of a dremmel with mounted point grinding wheel would help you access the pin without the need to remove the posts
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#5
From personal experience I would think long and hard before discounting Nick Turley's  advice.
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#6
Isn't bending the toggles the original manufacturers recommended service method?
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#7
I think it is the recommended method but new toggles are different material and snap before they bend unless heat is used.
Also I don't see why the linings and pillars need to be removed to adjust the levers' height.
Jim
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#8
Ive never done anything else but bend them hot. All in situ. The only thing you have to take off is the gearbox.
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#9
Amen Hedd.

 Bending can only be done properly with heat. It is the easiest way, the quickest way and the way Austin recommended to their dealer workshops.
It is the way John Dalby from Austin Seven Services always recommended to their customers.
It must be said that if the clutch backplate slots are badly worn (they often are) they need to be built up with weld something hard like stellite is good to use. 
Then of course machining out.
This ensures getting the lever fulcrum in the correct place.  
The correct distance from the lever to a straight edge across the back of the crankcase is exactly 1/4 inch and they must be exact!
I really hope this is helpful.
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#10
Out of interest I did speak to Seven Workshop and apparently both types of toggle are investment castings which surprised me as I'd expected the 3-speed ones would have been laser cut or wire eroded from plate but this may explain why some people are reporting they can crack if bent.

Although it's a bit of a pain to do I think I'm going to have to try to alter the height of the pegs as, apart from anything else, I don't have access to oxy-propane or similar to do the heating.

What concerns me a bit is that having re-measured both the dimension of the toggle lever ends below the "bell housing" face and also the corresponding depth of the slots over the repair pegs there doesn't seem to be much correlation.   I numbered the toggles 1-3 just for reference and have found:

Toggle 1 - Depth below bell housing = 4.88mm   Depth of slot over peg = 7.19mm
Toggle 2 - Depth below bell housing = 5.91mm   Depth of slot over peg = 7.12mm
Toggle 3 - Depth below bell housing = 6.72mm   Depth of slot over peg = 7.46mm

I have tried to determine the theoretical amount to take off each peg to compensate for the varying depths each toggle is below the bell housing which is dependent upon the ratio built into the toggles but haven't been able to get this to work.

I guess I'll just have to reduce the height of the pegs for toggles 1 & 2 so that they are all the same as toggle 3 and hope this brings all three toggles to the same dimension below the bell housing but I'm not that confident.

John.
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