Ideally the rod should be set when the gearbox is out of the frame...
Set the gearbox in top gear (4th) and remove the inspection plate on top of the gearbox so that you can see the layshaft....
The selector dog on the layshaft will be sitting between 1st and 2nd gear but will not be engaged with either...
You will see a gap on either side of the selector dog, between the selector dog and the face of 1st gears dog teeth and between the selector dog and the face of 2nd gears dog teeth..
These two gaps should be set as near to equal as possible by adjusting the threaded rod, winding it in the direction required to do so...
The assumption is of course, that the box has been correctly assembled and the shafts correctly shimmed before carrying out this procedure...
If the box is in the bike and has not been recently restored but is problematic when engaging a particular gear, the rod can be adjusted slightly to alter the degree of movement within the box and an improvement may be secured (or not)...
However, this is 'shooting in the dark' as you cannot actually see into the gearbox to determine exactly what you are doing and the problem may lie elsewhere anyway...Only move the rod in small increments, say one turn each time and keep track of how much you have altered it in case you need to put it back or make more adjustments...Ian
email (option): ian@wright52.plus.com
Got the gearbox back in and it worked better than ever, the gearchanges are more positive and also seem a bit easier than before. Thanks for the help Ian, this is a rare occasion, the bike actually works better than before I started working on it!
email (option): msawicki@mailer.fsu.edu
No, Florida State University in Tallahassee, but I did use your clutch spring compressor on the job!
email (option): msawicki@mailer.fsu.edu
Had a go at this today, think I've got this right, can anyone please confirm?
Gary.
email (option): gj.owen@hotmail.co.uk
It isn't clear from that photo whether you have the adjustment correctly set or not as only one side of the layshaft selector dog is visible...
It should lie in the center between 1st and 2nd gears....
Normally the gearbox is assembled and set with top gear engaged....At the moment in the photo the box is in 3rd. gear...
Ideally you should get yourself a set of the BSA factory worksheets for your model..This is all explained within...
Henk from this forum has them on CD at very reasonable cost...Ian
email (option): ian@wright52.plus.com
I notice also the gear with the lubrication drillings through it (3rd gear) is on the lay shaft whereas it should be on the main shaft...This gear can easily be mixed up with its opposite number (2nd gear), the only difference being the drillings through the gear and bush to provide lubrication..
Gears on the hollow lay shaft are lubricated via drillings in the shaft...3rd gear on the main shaft is lubricated via the drillings in the gear as the shaft itself is not drilled...
To avoid premature wear of the bush in the current 3rd gear (actually 2nd gear) these two should be swapped over...Ian
email (option): ian@wright52.plus.com
Gears on the hollow lay shaft are lubricated via drillings in the shaft...3rd gear on the main shaft is lubricated via the drillings in the gear as the shaft itself is not drilled...
To avoid premature wear of the bush in the current 3rd gear (actually 2nd gear) these two should be swapped over...Ian
Why is it when there are two ways of something fitting, I always seem to get it the wrong way round?
Think I need to get this back on the bench with the worksheet to hand and have another go - thanks for your help - much appreciated.
Gary.
email (option): gj.owen@hotmail.co.uk
['Why is it when there are two ways of something fitting, I always seem to get it the wrong way round?']..
Sods law never fails... ..In this case it's an easy mistake if you are not familiar with the gearbox as at first glance the gears appear the same....
I've just put the bottom half of a B33 engine together and didn't notice I'd picked up the wrong crankshaft assembly off the shelf, the later one with a half inch shorter conrod....
It only took a few seconds to work out what was wrong when I couldn't turn it over because the piston was hitting the the flywheels..DOH!... ...Ian
email (option): ian@wright52.plus.com