I got today a fully syncro tranny from a 54' Chevy truck. seems to be a SM 420 # GM 591907 with closed drive shaft and now i will swap my old crashbox. Where can i get rebuild parts for the tranny?
SM420s are real popular with the rock-crawling enthusiasts. I believe that 1st gear is NOT synchronized. Parts, history and maintenance tips are available at Novak among other places. http://www.novak-adapt.com/knowledge/sm420.htm
Muncie SM 420 Volker ~ before you begin , make sure the splines on the U-Joint you have , will mate to the new tranny . I'd replace the clutch whilst it's apart , be sure to use alingment pins when re - installing the tranny to avoid twisting the clutch disc and creating poor shifting .
Thanks Nate for this hint. I think i will count every grooves and check all spline before i cut my drive line. After the first view i think i have to cut the driveline. I have an U-Joint on my "new" tranny and will try to use this The clutch is new because i rebuild my old crashbox and if i have open any units i replace all other parts are reachable. New is new and i don't love it to make works double.
