Author Topic: Gearbox rebuild??  (Read 1474 times)

Offline Wylyetom

  • Moving Up
  • **
  • Join Date: Mar 2011
  • Posts: 17
  • Karma: 1
Gearbox rebuild??
« on: 17.01. 2012 11:48 »
Hi all, I hav'nt been on the forum for a while but my road rocket restoration is progressing well, the chap carrying out the work for me is now about to embark on the engine rebuild! My question here is about the gearbox, although it was a reasonably good change once warm
 Didn't like going into neutral , also when kicking over sometimes the lever would depress but nothing would turn? Due to this I have decided to get it stripped and checked, my question here is how difficult is it to carry out, my chap is very able with the use of our workshop, Orvis it a job for a professional if so who would be recommended, hope someone can help ,Tom.

Offline Topdad

  • bob hebdon
  • Wise & Enlightened
  • *
  • Join Date: May 2011
  • Posts: 2655
  • Karma: 36
  • l
Re: Gearbox rebuild??
« Reply #1 on: 17.01. 2012 12:46 »
Hi Tom, not being able to get neutral sounds more like clutch adjustment than the box particularly when you say it swops cogs ok. Have you looked at the clutch? Is the engine out yet if not you'll have to take the primary chaincase of so with case off pull in clutch lever and depress the kickstarter do the plates seperate easily ,when it spins round is everything even no to either of those and thats well on your way to sorting that out. re the gearchange lack of engaging anything first just try adjusting the cam plate adjuster ,slacken locknut and move adjuster out very slightly and try again don't move it much ,I think 2 threads should be visible. Otherwise take the outergearbox case of and have a look at the pawls on the mechanisan,spring even how tight the shaft is in the . The case comes off easliy but watch the kickstarter ,don'ttake it off rather use it to ease the case case then  unwind it when the case moves outwards and the kickstarter disengages ,you can use the clutch lever to jam then the case comes off complete with kick start and gearchange. if you need to go deeper or want to any way your guy should be more than capable to strip the box. with the help of poeple here on this site I did my own last year and had never looked inside a gearbox before. Best of luck BobH
" rules are made for the guidance of wise men and the blind obediance of fools"
United Kingdom

Offline Goldy

  • Warwickshire, England
  • Resident Legend
  • *****
  • Join Date: Dec 2008
  • Posts: 619
  • Karma: 9
Re: Gearbox rebuild??
« Reply #2 on: 17.01. 2012 20:11 »
Many gearbox faults seem to be caused by the selector mechanism. As Topdad says check the selector pawls for wear and ensure that the selector spindle turns freely and is not binding. It is not difficult to strip the gearbox, once the outer and inner end covers are removed the two shafts slide out. The main thing is to catch the two selector forks and spindle as they fall out. Take lots of phots with a digital camera as you proceed and follow the service sheet. All the best Goldy.
56 A10 Golden Flash - Restore, ride, relive.                                          
56 C12 BSA project ongoing

Offline Wylyetom

  • Moving Up
  • **
  • Join Date: Mar 2011
  • Posts: 17
  • Karma: 1
Re: Gearbox rebuild??
« Reply #3 on: 18.01. 2012 07:56 »
Thanks topdad and goldy, I know that the clutch is fine as having owned and ridden the bike for eight years the clutch has been apart a few times, I thank you both as this has given me confidence to go ahead and have my man strip it down, my worry about gearboxes comes from my short time at college when I had to strip a jcb matbro box, when opened everything fell out, I'm sure some of the parts are still hidden under the work bench!