I have a '53 3100 1/2 ton pickup. SM420 transmission with column shift.
I've posted before about this and have learned a lot and tried a lot so far. I actually have come a long way in "dialing in" my shift linkage and transmission issues.
Shifter, shift box, and linkage are all set up according to the shop manual and I'm using 90w mineral oil from NAPA in the transmission.
Shifting to reverse, 1st, and 2nd are always smooth. When the truck is cold (been sitting for a day or so) 3rd gear is smooth too. As the engine and transmission warm up, 3rd gear grinds increasingly and steadily. It never gets too bad though and if I ease it in, I can get it into 3rd with almost no grind.
I always double clutch because I learned to drive it that way and it's second nature now. It doesn't matter though, 3rd always acts this way. Would this be a bad 3rd gear synchro even thought I'm double clutching?
Last edited by mattconrad5150; 09/03/2016 7:33 PM.
