1952 Tiger 100 Crankshaft Nut

petetherev · Aug 1, 2014

Hello, I have a question re a 1952 Tiger 100 engine No 31640. This engine originally had a ‘small bearing crank’ but I changed it 45 years or so ago for a ‘big bearing crank’. If I remember correctly I had to bore out the main bearing housings to accept the larger bearings. I fitted it in a Gold Star and it has been gathering dust in my garage for more than 40 years. My problem is that I can’t remember if the crankshaft pinion nut is a left or right hand thread. I know that the camshafts have left hand threads and the crankshaft rotates in the same direction so logic suggests the crankshaft pinion would be the same although there is no marking on it, and I can't shift it, either way. I'm stripping the engine on the bench so I can't get a lot of purchase on my own.
I did read that on the unit engines the crankshaft did in fact have a right hand thread.

Any help would be appreciated.Tthank you
Regards

Recycled Rocker · Aug 2, 2014

Howdy did a bit of scroobying round, I think yer got yer anwer "Your crankshaft drive end is right hand thread."
from BritBike.com website Triumph BSA Norton glad yer got it sorted, I'm doin surgey on a 1963 6T and faced same thing...good luck, try a bigger 'ammer :upyeah:

petetherev · Aug 3, 2014

Hello Recycled Rocker, thanks for your reply. You were correct it is a right handed thread. I managed to get it offi must have been a lot stronger when I put it on. Engine now completely stripped and cleaned ready to rebuild.

Thanks once again.
Regards
Pete