Triumphrat

gumpt1oo

Hi Guys, I have recently bought a 1979 T140. It needed new chain and sprockets, so after watching Plewsy's excellent clutch removal video, I set about changing the sprockets. I successfully removed the clutch and the circular cover to access the front sprocket.
Got the big nut off the shaft and the sprocket will not fit through the hole in the casing!
The new sprocket Is a 20 tooth the same as the original and it just fits through the cover.
The diameter of the old sprocket is about 1mm to big. Anyone come across this problem before?
The only way around as I can see is to run a dremel around the casing until the sprocket comes through.
All advice welcome!

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We're all doomed!

daveforty

If the old sprocket is that much oversize, then I guess whoever assembled the thing must have done it by taking the gearbox out and removing the mainshaft sleeve (5th) gear and re-assembling the gearbox with the sprocket in place. You may have to do the same to get it apart. Not complicated work, just long winded. I wouldn't suggest taking a Dremel to the cases. Someone got the oversize sprocket in there - you can get it out.....

tangomike

If you are going to use a dremel tool, use a cutoff wheel on the front sprocket and leave the case alone. What's that you say?? Sounds like a lot of work?? I'm sure it is. I used a dremel to cut a hunk of chain out that was seriously wedged between the case and the sprocket.

TangoMike

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If it's not leaking oil, there ain't none in it.

pookybear

Gumpt100,

Yes you are most right the new sprockets at the 20 tooth size just
squeeze through. So a dismantal of the transmission to remove
a larger sprocket is the proper way. Now back to the way everyone
else does things. Twenty small notches can be cut to get the
larger sprocket out. Make sure the notches have no sharp edges
and everything is nicely rounded. Or....

You can take that dremel of your and cut down the old sprockets
teeth and save your cases. As I would think you are replacing the
sprocket to put it into the trash so who cares if you grind on the
sprocket.

Pookybear

gumpt1oo

Thanks guys, mission accomplished! On closer inspection, and after cleaning all the crap off, there were 20 small marks around the casing, it was just a matter of turning the sprocket around until the right position was lined up and it squeezed through the hole!

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We're all doomed!

pookybear

Well,

Easy Breezy, when someone else does the work for you. That is
great.

pookybear