gb 40 gearbox

[JimWalsh]

i have a gb 40 gearbox and a 3plate clutch what length should the push rod be i have 10 and 5/16 plus the ball bearing but when all together i cant move the clutch lever it is solid regards Jim

[Pete.Silson]

Jim

GB40 box so I assume we are talking single or twin cylinder engine. My info lists 9-11/16" for 1952-55 and 9-13/16 for 1956-58 singles with a 3-plate clutch.

10-1/4" is for a SQ4 I think.

Pete

[keith.mettam]

Jim,
GB40 box was originally fitted to 1956-57 KH, 56-58 VH and VB models. With a three plate clutch draganfly's site shows the pushrod as being 9 13/16" long with a single ball bearing at the gearbox clutch operating lever side of the pushrod. Remember to adjust some free play here by removing the two screws holding the small cap on the outer gearbox cover and moving the hex-nut one way or the other to give a little free play at the operating lever. Check this free play at the end of the clutch lever through the gearbox oil filler cap. A point to note as you have been working on the gearbox, make sure the clutch lever under the outer gearbox cover has engaged with the slots in the little plunger that slips in the mainshaft hole for the pushrod otherwise the clutch won't work.



Regards,
Keith.

[JimWalsh]

i am not sure if these parts have allways lived together i got the bike in boxes,it was not in good condition dont know if it was a built up bike then taken apart or bits collected over the years fork bottoms was for a350 with the smaller diameter spindle and single sided front wheel, timing cover from HS, and NH fork top instead of the divers helmet type,i have rebuilt the wheels with FWHs and the whole bike is built just the niggley bits now which can turn out to be the worst bits but i will get there and let you know how it goes regards Jim

[JimWalsh]

well it seems that something must be amiss first the clutch lever arm inside the gearbox was round the wrong way)ie the little knobblely bit on the arm ) was not faceing the clutch,i turned this over and had too much play as opposed to not enough it meant that i had to put an extra 5/16 ball in which now makes the rod 10 and 5?8 i don't suppose that matters as i all works fine all gears select and clutch clears.i need the 4 rubbers that the tank bolts down on ,also the centre tank mounting kit if anyone has them. regards Jim