Hitchcocks Forum

hello all, been out for my first blast of the year this weekend,bike is running pretty nicely at the moment but i noticed last year that it occasionally slipped out of 4th gear into a false neutral. On my ride yesterday this happened a number of times including one time when it slipped from 4th to 3rd....that gave me a fright! Could you guys suggest where I need to start looking? I have very little knowledge of gearboxes. Many thanks Richard

Richard, if you really have no knowledge of gearboxes, probably the best place to start Looking is for someone who has the knowledge. Not trying to be funny but if you don't know then it's best to be shown rather than advised from a distance, give a rough area where you are and someone may offer help.

Richard, you need to tell us a bit more. Is this problem completely new? What is the history of the bike in your ownership? Dennis is probably suggesting that there are a wide range of possibilities that might explain your problem but we do need to know more. Possible problems could be: faulty detent plunger, worn selector quadrant, failing layshaft bush and possible failing mainshaft bearings. Or maybe none of the above! First thing I'd do is drop the oil out of it and see what's in it. Bronze coloured? Silver flakes? Mayonnaise? Good luck!

REgards, Mark

hi gents sorry for the late reply, first time back to my computer since last week. Since my ownership the bike has covered no more than 100 miles and before that it hadn't been used in 30 years! With help from you guys over the last 18 months or so, I have managed to get the bike running nicely but I fear the gearbox problem was always there, I just put it down to not being used to an old british bike! Now I can get the bike up to speed and go further, the slipping out of 4th gear is much more noticeable. I will do as you suggest Mark and drain the oil and let you know. Thanks again Richard

Slipping out of 4th must be a nightmare, as this is the gear which I recommend you select asap to preserve the gbox. It puts the least strain on the whole box, as in 4th the mainshaft does not rotate within the sleeve gear & the drive bypasses the layshaft).
I would guess that the selector dogs on the sliding 3rd gear & fixed 4th gear on the mainshaft are likely worn. The effect of this is to repel the two gears apart. If you do have to go into the box to check this, then you may as well check the whole box whilst you're in there. Sounds like it needs an overhaul.
TTFN Jack