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MK3 Interstate gearbox

Submitted by robert_rouse on Thu, 22/12/2022
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Commando

Hi 

This is my first post on this forum, My 1977 MK3 Interstate has done the 47k miles, not sedate miles but not drag raced, Ive owned it for about ten years and I’m a bit concerned about the lay shaft bearing that seems to have achieved some notoriety among other owners! So do not want the experience of the rear wheel coming to a halt while riding I thought I’d preempt that and get it fixed.

I’m located in North Kent/ SE London area I can remove the gearbox myself but like all he bearings and a full inspection done professionally. My son now in his late twenties has started to ride the bike and has forsaken his GSXR for the Commando.

Does anybody have any recommendations for someone who could do a gearbox rebuild as the time isn’t available for me to do it?

Bob

Submitted by robert_tuck on Fri, 23/12/2022

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Proffesionals prepared to work on old bikes are getting fewer by the day.  I would pitch in and  get it done. There are club members locally who would likely   help with any issues. I dont think its absolutely necessary to remove the box . Others with more experience of the later box will chip in with more advice. 

Submitted by tony_ripley on Sat, 24/12/2022

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Hi Robert,

I know a chap who will do it for you and I would highly recommend him. I will send you his details via a private message. 

Regards

Tony

 

Submitted by peter_shand on Sat, 19/08/2023

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If the box is out of the bike and you have the correct tools it takes less than an hour to have the box fully stripped. It is when you have to cope with what others have done before is when it takes longer. If the box is out of the bike and the kickstart and gear levers are removed its five 1/4" screws and the outer cover is ready for off. Then the clutch mechanism lock ring (this is usually chewed up as others have been at it with a hammer and punch) Then the mainshaft nut underneath this. Then the seven 5/16" nuts holding the inner cover removed and the cover removed, NOT by hammering a screwdriver into the joint. Cover removed and the selector rod unscrewed and removed and the gearcluster and selectors can now be removed. Heat the case at the drive side with a hot air gun etc and bump the case on a wooden bench to remove the drive side case bearings. The only special tool needed is the one for the clutch mechanism lock ring and that can be made if you can wield a hack saw and have some steel pipe handy. The service notes recently serialised in roadholder has a drawing for this tool.     

 


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