New Triumph Crankshaft Pinion Nut. This is a very high quality part made to replace Triumph part number 70-0398, E398 and E0398. Fits on the timing side of the crankshaft to retain the pinion gear. Manufactured in the England by L.F. Harris to exceed O.E.M. specifications. 

Measures 3/4" X 20 TPI. Suited for various for Triumph Pre-Unit twins (5T, 6T, T110, T120, etc). Please refer to your parts catalog for proper fitment.