gear box sprocket help

padlock

padlock

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Location
bedford Uk
Hi all, have just removed the clutch cover to change the gearbox sprocket and the sprocket itself seems to have a large amount of play on the shaft. Is this normal? 
 
          FFF
 
But rest assured it is not the worn sprocket you're replacing that is shot, it's the output shaft...FFF :D

piet
 
Andy Wagner used to sell sprockets with undersized splines for just this scenario, although I can't find them in his current online catalogue. Considering that this is probably the last time you'll replace the sprocket, you might want to consider this option. Andy wants quite a lot of money for a new mainshaft, although complete used gearboxes do come up fairly often on eBay.
Or, I'm prepared to dispose of the now-useless motor for you if you ship it to me. I won't even charge you for it. I'll PM you with my address.

Ken
 
It's a crankcase-splitting job to relace the sleeve gear. Peculiarly with Oriental tat is usually the sprocket that's rubber-ducked and not the output shaft splines. In my limited experience with H***as the sprocket is ludicrously sloppy from new.....just gets sloppier !.
 
padlock said:
Tell me more, i could do with a drink.
Click to expand...

Padlock,

It is not at all uncommon.....seen it on triples ever since they were a few years old only. Those big old 630 chains placed a huge strain on everything and, although the 630 sprocket has a bigger surface area than 530, they still chattered away on the output shaft splines.

You might be lucky and it was a cheap sprocket that has worn, but it's not usually the case.  If you are confident that you can centre a new sprocket perfectly, why don't you tack weld one on?  Not got much to lose and it could last for years.

Pete
 
I encountered exactly your problem, evident by a lot of backlash felt at the rear wheel - about 150 mm of rotational movement.  The 5th gear output shaft splines were completely shot with a pronounced step at only 28 000 km.  The 630 sprocket did not look too bad but the locking washer was (inevitably) a mess.  I got a replacement 5th gear from a supplier in Norfolk (the last one he had) and that cost me a whopping ?345.00 about 3 years ago.

Andy 
 
 
When I converted my Jota to 530, there was significant play on the shaft-630 sprocket. 
I replaced the 630 with a 530 sprocket that I sourced from Wolfgang about three years ago.   
The 530 sprocket was a tight fit and there was no play evident.
Interestingly, another 530 sprocket that I sourced on the web did have some, but less, play.
I think this is more of an issue on 630 bikes.  I've never had an issue on my 3C.
 
I just changed the output spline on my 1200 cause the sprocket was loose. 1st 100k kays with a 630 and the last 70k with a 530 but the damage was done before changing to 530. It was never an issue and only changed mine as I had the cases apart anyway and had a spare set of 1200 gears on the shelf.
 
Well it would appear that things are not quite as bad as i first feared. Got round to getting the(completely fucked) locking washer off. It had worn almost completely through!!!! The sprocket itself had worn quite badly and there is some wear on the spline but with the new sprocket on the free play is tiny.
  I'm taking the bike up to Keith's in April for another bout of hemorrhaging money so will take his advice on weather it can run like it is or not. Keeping in mind that it only has to hold together for a few hundred miles so i can make sure that the rest of the build works before it's ripped apart again for final finishing and the engine is stripped and rebuilt from the crank up.Word to your grandparents.

      FFF
 
Just had a closer look at the sprocket( only had two beers so can still see properly) not only is it very worn its a 17 tooth sprocket as opposed to 19???????

  FFF
 
padlock said:
Just had a closer look at the sprocket( only had two beers so can still see properly) not only is it very worn its a 17 tooth sprocket as opposed to 19???????

   FFF
Click to expand...

count again when sober, should be 16 tooth x 630 pitch
or 19 tooth x 530 pitch
those are the two standard front sprockets available


 
Ha ha ha ha ha ha ha ha ha, I'm a twat(no comments please) apparently I can't count. There's a reason I'm a tree surgeon and not an accountant.

FFF
 
When I converted my RGS from 630 to 530 it too had significant wear on the splines. I coated everything with a thick Molybdenum disulfide grease when the new sprocket was fitted. I re-grease every few thousand miles an no new wear has occurred. One day I will split the cases and have the output gear splines welded with hard face and the splines re ground. For now this works fine.

Bruce
 
Thats exactly what I do with mine Bruce, no significant wear since starting the greasing routine.

Terry
 
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