MKIII Gearbox removal / overhaul

Hi, I was just about to go for ride this afternoon when the kickstart splines gave up - the spline on the shaft is untouched!!
Having had the kickstart kick my heel quite a bit recently and finding bronze glitter in the oil last time I changed the oil, I reckon that it might be time after 30k to refurbish the box. Havin had a look at variuos kits they seem to contain different levels of bushes etc. Being an engineer my mind says 'whilst it's apart change all bushes, bearings and seals' but having just priced this lot up on the andover norton website it comes to a considerable amount. What I would like to know is how easy is it to remove the gearbox, and are there any problem spots within the gearbox that wear worse than others, has anyone bought a kit and found that they needed additional bushes after stripping the box? Any help and advice will be well appreciated.

Madnorton said:

What I would like to know is how easy is it to remove the gearbox

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If you follow the directions given in the factory manual, then the job should be reasonably straightforward?

Madnorton said:

has anyone bought a kit and found that they needed additional bushes after stripping the box?

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Why not just strip it down first and see what parts you need?

If you phone Mick (or Angela) Hemmings with your parts order, you will probably get your parts the next day, or the day after.


http://www.mhm.demon.co.uk/

Mick's instructional video on the subject is quite helpful for us neophytes also. Great written instructions on the Old Britts website. Either will do you fine; both are a great combination. Best of luck - it's not hard, but there can be some challenges along the way - Mick's video is especially good on those.

If you're going to replace all the bearings be very wary of buying a complete bearing or bush kit, you'll more than likely get a collection of poorly fitting pattern parts.

It appears this could have been a wise move. I have removed the gearbox without undoing the rear engine mounting bolts with the bike on the centre stand. Once I got it twisting it moved relatively eaasily anti-clockwise and would have come striaght out if the oil pipes were not in the way. On stripping the box, the bush in the kickstart shaft is well scored and worn, 1ST gear bush on layshaft is well worn, the FAG layshaft bearing on the nearside is well worn ( rattling fit ) and the other bearings are not brilliant. The gear teeth show no signs of wear. So I'll just purcahse my what I need, specifying high grade C3 clearance, extended life bearings, hopefully NKN will do them like the rest of their extened life stuff, they are the same as C3 bearings but have been treated for a massive life span - costly but worth it, I think. When my box was last fitted with FAG bearings I don't know but must have been soon after registration as the previous owner had it from '79 -'95 and it was not i his notes like the swing arm bearing mod that he done.