evening all, brand new to the forum so bare with me. i pulled the box on my lemans mk11 replaced all bearings (ouch) and shimmed it as best i can, now the selector drum was not shimmed enough at the clutch end of the box leaving wear marks on the clutch side of (fourth) and (second). my question being is it worth investing in two new forks(£300) made of solid gold? the forks measure a shade over 5mm on my calipers, and are measuring 4.8mm approx where they are worn, would you consider that a problem? any thought from you guys would be great. kind regards russ
I did the reshim of the selector drum on my Spada a few years ago and barely noticed any difference. I wouldn’t worry about .2mm wear, they operate over a large area and that tiny amount of extra movement is unlikely to make any difference.
hey thanks don,did you do anything else to improve shift? or do you live with it? i pulled mine because it was a distraction getting fase neutrals just about every time im going up the box even if im shifting slow regards russ
I did nothing else. I had the box out as I snapped the clutch arm lug off trying to shift the clevis pin so changed the cover. As I was that far in I thought lets give it a go.Always change the return spring when your in there, but I’m sure you have done that. If the problem is always in one direction, then it could be worth while trying the adjustor on the back of the box to centralise the pawls that engage onto the selector drum pins. This should be done with great care and a tiny bit at a time. Guzziology tells you how to adjust it if you have access to a copy.
thanks don, new spring is on havent touched the pawl adjuster yet but i can see the offset is not much maybe 1/4 turn max. maybe ill re use my forks see how she goes regards russ
Where abouts are you, Is it worth trying another bike to see what the box is like, I’m East Mids South Leicestershire based.What mileage has the bike done?
thanks for the offer Don, im down in cardiff, might be a bit too far. regards russ
Correct clutch adjustment can help gear changing enormously - start at the back of the box, make sure the grub screw in the gearbox clutch arm is dead inline with the pushrod, especially when fully depressed. Then get the bottom clutch cable adjuster sorted, then the clutch lever adjuster. On mine at least there’s a ‘sweet spot’ deviate from this and gear changing starts getting notchy.
Also does the pedal have enough free movement on the up changes, or it may be set too high?
Mike H2014-10-08 13:56:56
Pete Roper’s article is good, but there are alternative approaches.There is a good article by John Noble at http://www.thisoldtractor.com/guzzitech.dk/pdf/gearbox-rebuilding-john-noble.pd.Also an alternative method of shimming by Charlie Cole. http://archive.guzzitech.com/shimming-charliecole.htmlIn practice the wear you mention is not likely to be critical. As Charlie points out all you can do is visually even up the clearances, and if all gears select properly and there is no scary movement then all is OK. Who wants just one neutral anyway?(BTW: Just finished doing my box after a clutch job and breaking the clutch arm lug (Ham-Fisted!) Now changes as sweet as anything).
hi mike, good info on the clutch. as i understand it the lever should be at about 8 o clock give or take , what do you rekon regards russ
did you use the method you mention regards russ
If you’re asking me? Yes. Not sure about “8 o’clock” though. We had this long thread couple of years ago about what is the correct distance between end of g/box clutch arm and the cable anchor lugs. My MG workshop manual says 75mm, but in practice this is way too much, there’s not enough room between g/box and frame! I think in the end it ended up as 54mm, but whatever it is, the point is to get the grub screw inline with the direction of the clutch pushrod. HTH
Mike H2014-10-08 18:47:21
sorry mike i meant the pawl lever at about 8 oclock for max up and down movment. i just been in the man shed looking through the oil filler hole on the box,after much shim swaping i have 2.2mm at clutch end of drum and .2mm at the cover end (not including the lrge flat washer holding he pins in) this set up gives an even engagement for first and second and no binding but given that the forks are not a snug fit in the dogs their is a small amount of play in the neutral position, i think thats good to go so ill put new seals etc regards russ
new peg nut socket just came from shebay nice £13
Oh I see, (re pawl) I have no idea! Sorry.