the trans in question is a 71 bonnie 4 speed. my main shaft measures .809-.810 where it goes thru the top gear pinion, the pinion measures .816 on the threaded end and .8175 on the gear end. I can't find in the manual what the tolerance is anybody know?
Are referring to the drive end side of the mainshaft and the bushing ID on the mainshaft high gear? If so according to my 71 triumph manual for the 4 speed gearbox the left end diameter of the main shaft should be .8098/.8103 and the main shaft high gear bore should .8135/.8145. Hope this helps.