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*?&|" 5 Speed Gearbox Clutch Adjustment

Posted: Sun Feb 03, 2019 3:03 pm
by Andy C
I have had to reduce the length of the clutch pushrod when I replaced the old 4 speed box with a 5 speeder on my 612.

Possibly because of the Newby clutch the standard pushrod is too long, and for the Nth time now I have had to remove the pushrod to reduce it's length, currently I run just out of cable adjustment, and since the adjuster in the clutch pressure plate is backed right in the only solution is to take a little more off the pushrod.

Found an easy way to remove the pushrod from the clutch side - a small cylindrical magnet on the end of a steel rod pushed in from the clutch side, only problem was that I managed to move the clutch arm out too far on the gearbox side, so much in fact that I heard a familiar "tick tick" as one or more of the balls from the clutch mechanism fell out of the housing.

Drain the geardox oil again and take the cover off again.

Damn it - hopefully make the pushrod the right legth this time !!!

Posted: Sun Feb 03, 2019 3:46 pm
by stinkwheel
You hardening the cut end of it too? Not sure if it's strictly necessary but it can't hurt. I made a new pushrod for my latest bike out of EN8 and hardened the ends. I made it in two pieces like they used on later models to help reduce the likleyhood of bending. I also used ceramic bearings to reduce heat transmission. Perhaps this is overkill, but it wasn't an expensive or time consuming thing to do.



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Hope it's right for you this time!

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Posted: Sun Feb 03, 2019 4:00 pm
by Andy C
Mine is also a 2 piece, I dont have the ceramic ball, but do have a standard steel ball. I did harden the ends when I made the rods originally but not bothered each time I reduce the length to try and re harden. Thinking being that as I am only reducing the length by around 1mm each time with careful use of an angle grinder - i.e. not trying to heat the rod too much it does not need to be re heat treated. Once I have established the correct length of the rod that I keep reducing in length I will most likely make a new one and harden both ends. May even invest in a ceramic ball.........

*?&|

Posted: Sun Feb 03, 2019 11:04 pm
by Leon Novello
Just out of curiosity, Andy, at work years ago, we used a product called Hardite for hardening pivots on weighing machine levers (on Dayton scales). Heat to cherry-red, dip in Hardite then dip in water. What is used these days if Hardite is not available?


Oh! and I suppose you could always fit a larger ball if you grind too much off a rod.

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Posted: Mon Feb 04, 2019 1:48 pm
by stinkwheel
Well I go with heat to cherry red, quench (I used oil), scratch the surface once fully cool (which is what they're doing in the picture above) then re-heat slowly to the appropriate colour and allow to cool slowly. I went for purple-ish.