I've got a 1951 Chevy 5700 COE that has the SM420 four-speed. I rebuilt and reinstalled in the truck and cannot seem to get it into neutral, or more simply, just out of gear. Here are some images I just took, and I know I need to lube the hell out of the linkage and add oil, but I'm hoping to get it into neutral before doing so. Anyone help with what the 'starting point' for both the gears and the linkage should look like when in NEUTRAL?
Hello Derek, Make sure your shifter top yokes are in neutral, they are in neutral when the outside of the 3-4 yoke to the outside of the 1-2 yoke is 4-7/16". Then based on the third picture, your 3-4 clutch slider is indeed in neutral, move (slide) the first gear forward on the mainshaft so outside of the 1-2 shifter groove is 4-7/16" to the outside of the 3-4 clutch slider, then drop the top loader yokes down over the sliders while making sure the reverse lever fits inside the head of the toploader. Done deal
Steve
Last edited by sstock; 08/07/20191:02 AM.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
Well im no expert tranny mechanic but it looks like you might have it in reverse or 1st. The big gear in front is engaged into the secondary shaft gear. Kinda of hard to get a "feel" for what should be and not via pics. I think if you have the knowhow todo a rebuild you can see whats going on. Use a screw driver to move things around while turning the output shaft and im sure it will all sync together.
Thx Steve. I updated two pics to show what I think you're telling me to do. Can you confirm? Please open the images so you can read what I've typed on them.
glennstowing - thank you, I was seeing what would move and what wouldn't after I removed the top cover and I accidentally slid the reverse lever and gear forward, but didn't move it back before taking the pic.
Almost right Derek, OUTSIDE OF THE FACE OF THE YOKES AND OUTER GROOVE OF THE SLIDERS, I changed your picture to show it. Then yes move 1st gear left or right on the mainshaft by sliding it to obtain the 4-7/16" dimension. When the top cover is in neutral, the 1-2 yoke will be in the center detent, as well as the 3-4 yoke and that dimension should be 4-7/16"
Last edited by sstock; 08/07/20191:48 PM.
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
1953 Chevrolet 3100 261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY Gallery Video of the 261 running
1964 GMC 1000 305 Big Block V6, sm420, the next cab off restoration
