Transmission Identification help

[maddmaxx1949]

Hey fellas, need help Identifying a couple of transmissions dad and I own. Got them from an old farmer with a couple of 250's a number of years ago. I used the one pictured with a 218 to drive a frame around and I'd like some info. I'm not sure if the thing come down and off to the side is for 4wd or a PTO maybe?

[Merle Coggins]

That looks like an early New Process, spur gear (not synchronized) 4 speed. And yes, the gizmo hanging off the right side is a PTO. 

[Dozerman51]

Easy way to tell a synchronized from a non-synchronized PH 4 speed is to look at the drain plug. A synchronized unit has the drain plug running horizontal at the bottom rear of the case while a non-synchronized unit has the drain plug running at an angle in the same general area. At least that is what the parts book shows talks about.

[maddmaxx1949]

I'll check on the drain plug tomorrow. I'll dig up the other one and see if its the same exact as it might not be. Need to research the difference between synchro and non sychro as I have no idea what that means. Is the 3-24-49 the date of manufacture? and is there a way to tell what a transmission is just by the cast number? I've had a nightmare of a time trying to ID a 3 speed from a coronet with just google

 

[Merle Coggins]

Yes, that's likely the casting date of the case. I've never seen a model ID listed for these transmissions. They're just New Process 4 speeds. I believe the later version is refered to as the NP420. Non-synchro vs. synchronized transmissions refers to how the sliding gears function. In the early spur gear, non-synchronized transmissions the gears have straight cut teeth and there are no synchronizers to aid in shifting. With these transmissions you need to learn the art of double clutching your shifts. The later, synchronized, version was introduced into the Dodge trucks in '51. This transmission has helical cut gear teeth for quieter operation and syncronizers on 3rd and 4th gears for easier shifting. Pretty much all modern transmissions are of this synchronized type now. 

 

Another way to know the difference, and how I identified this one, is that on the earlier spur gear units the PTO drive was ahead of the fill/level plug whereas the later, synchronized, units have the PTO moved rearward with the fill/level plug towards the front. 

Edited June 24, 2020 by Merle Coggins