Hi all,
Looking for some advice. 1929 500 twin port sloper. 3 speed box. I bought it a year ago, supposedly restored, but have come across no end of bodges but have managed to surmount them all but can find little info on the 3 speed box and clutch. The problem is that there is end float on the gearbox mainshaft of about 30thou. Is this acceptable or excessive? The reason for delving into this is the clutch is dragging. It seems there is not enough throw on the handlebar lever to open the clutch fully. All the plates are new and flat. Plate stack height seems about right. No notches on the castellations and the levers are believed to be genuine. Can anyone advise if the end float is ok and if not what the solution might be and can anyone tell me what the pivot to nipple distance should be on the clutch handlebar lever if mine is wrong?
Cheers
Andy
It sounds like there's a shim or spacer missing from the mainshaft. I'm not totally familiar with this gearbox, but I would think that the mainshaft should have no more that a few thousandths endfloat - 10 thou max.
The pivot distance on my 1930 model is 1". My view is that 0.030" endfloat is far too much, particularly if you've not measured it dry. This will reduce your clutch throwout by the same amount.
It's suggested that mainshaft endfloat should be between 0.001" and 0.003" dry. However, this seems a little tight to me, so I set mine to 0.005". Once set I would ensure that the endfloat is maintained when turning the mainshaft. Watch out for tight spots.
You might want to check sprocket alignment, to see which way the mainshaft needs to move.
There are 2 washers between the sleeve gear and the mainshaft. The one that sits against the sleeve gear M144A is a phosphor bronze washer, and mine was 0.093" thick. The one that goes next to it 25-4088 is a hardened steel washer, and mine was about 0.087" thick, but please avoid using shims here. They will just break up.
Alternatively, you could remove the tophat bush in the outer cover and fit a shim behind it, to move the mainshaft the other way.
Also, adjust the clutch arm and cable so that, with the clutch fully withdrawn, there is a right angle between the arm and the pushrod. Every little helps.
Let us know how you get on.
Steve.
Thanks for the comments.
My lever centre is 1" as well so that can be crossed off.
I will strip the gearbox this coming weekend and report my findings.
A bit late but an update.
The mainshaft has been shimmed to give 8 thou and seems fine. The clutch however is OK but right on the cusp of engaged (lever out and a few thou free play at the pushrod arm) and just at the point of disengagement with the lever fully in. When out for a ride and things heat up i am back to slight drag. Better than it was but not good enough. I have plenty of post war clutches, Triumph, Norton, NEB etc and was considering converting to one of those as the throw available is ample to disengage one of those. Anyone else done it?
By the way, The clutch itself is fully functional and all the plates are new/good. No notches or wear that I can find anywhere else.
Cheers
Andy
Andy,
I've always found the clutch disengagement to be marginal on my Sloper, and can only tell you what I've done to try to cure it. I have found that a series of tiny increments add up to acceptable disengagement.
Firstly, make sure the pushrod is 11 17/64" long. I believe the original rods were dimpled at the end, so preventing the rod moving across the face of the 5/16" ball.
I rebushed the threaded bronze bush in the end cover, and rebushed the withdrawl arm pivot.
I made sure there was no play in the handlebar lever pivot, and that all the steel plates were flat.
I had some new friction discs made (but have yet to use them). Rather than being 1/8" thick, I imagine that they use metric material. If they have used ,say, 3.5 mm material, (0.3mm X 7 =2.1mm) giving 2.1mm extra height to the clutch pack. I wonder if this might make a difference to disengagement? It's all to do with leverage, moments and angles. I tend to use the original plates boiled in washing powder.
Although the clutch assembly seems well shrouded from oil ingress and depending on how much oil is coming out of your breather, I find that any oil on the plates causes disengagement problems.
Finally, you could try playing around with the adjustment of the pushrod adjustment screw and cable adjuster, and try different arm angles.
Is there any play in the clutch bearing?
I'm not sure if any of this will help you, but it's all I can think of.
When it comes to the end gap on the gearbox primary, it's usually no more than 5-10 thousandths of an inch. Therefore, 30 thousandths of an inch is a significant gap. It may seem to cause the clutch to pull or not work properly. A possible solution may be to require or adjust the bearings first. If you are experienced in auto repair, you can try to do the job yourself. If not, it is recommended to a professional mechanic to diagnose and repair the transmission. Regarding the interaction between the axle and the nipple on the clutch lever, this may be due to specific motorcycle models and components found in your clutch system. It is best to highlight for use or to mechanics to know the greatness of your motorcycle.
Thank you for your replies. It is interesting that others have found the clutch marginal too.
I have removed all the excess play from the bearings and bushes. The lever pivot and etc.
The pushrod is dished so as not to 'ride' the ball. I think it just needs a few additional millimeters of lift to make it work well.
I will see how the improvements work when the weather improves. If it is not good enough then I will get on the lathe and make
an adaptor for a different clutch that needs less movement to lift. I will post progress.