The Stovebolt Site Forums The Shop Area Engine Shop transmission swap on my '54?

I'm new to this forum and my truck. I have a '54 3100. It has a three speed mounted to the torque tube. I acquired a four speed which could be a '54 or a '49. It came out of a '49, but there was a '54 235 in that truck so I am not sure of the year of the trans. Question is, can I mount the four speed to the torque tube in my '54 without modification of the driveshaft/torque tube? Do these transmissions swap easily? The splines on the input shaft are the same, I just need to know if it will bolt up before I drop the engine/trans assembly into the truck.

Andy

Andyman,

Yes, that transmission, if it has the torque-tube fitting at the rear, will work on your truck. No modifications would be necessary, and it is a fairly easy swap (although. the 4-speed is at least twice as heavy to lift).

You will need a 4-speed 1/2 ton u-joint. If the '49 was a 1/2 ton, that u-joint will work.

If you do not mind my asking, why do you want the 4-speed? Is your three speed giving you problems?

Thanks, Tim

Tim,

This project is my boy's (ages 12, 11, 9) and my daughter's (age 4) truck. Thsy are pumped about it. I just like the idea of the floor shift versus the column shift. I am putting this truck together from several trucks. The good sheet metal truck is a '55 first series Old Navy display truck, but EVERYTHING has been cut off the frame and the truck is just a shell. I bought a '54 junker for peanuts that had no motor or bed but everything on the frame and cab to complete the project (including a nice grill assembly). The junker has a three speed attached to the torque tube, but I have no idea of it's condition. I bought a flywheel, clutch and 4-speed trans assembly for peanuts from a youngster hot-rodder. I really just needed the bell housing and flywheel, but the guy through in the tranny for nothing. Pulled the cover off the 4-speed and it looks brand new inside. Plus, he drove that truck and reports trans shifted well and drove well. My junker truck has horrible sheet metal with much rot on cab, fenders, etc. Doors are practically falling off as lower hinges have nothing to attach to. Plan is to remove junker sheet metal, install engine (from a '58) and trans assembly and put the Old Navy body parts on the junker frame. Using the 4-speed just makes a cooler truck for the kids. They never heard of a "3 on the tree", but a floor shift 4-speed they can relate to. Plus, there is some question about whether or not I have all the linkage parts for the column shift as much of the junker parts on in boxes that I haven't gone through yet. I have also read about problems some of you guys have with 50 plus year old linkages working right on the three speeds.

Here's another question for you since you answered my first: The flywheel and clutch assembly for the four speed is larger than the three speed (I am not in the garage so I don't have exact measurements). splines are the same for both trannys. Can I use either flywheel and clutch assembly or do I have to use the one that matches the trans? I think one is a nine inch and the other a ten inch, but am not sure.

Andy

Andy,

You can use the larger clutch and flywheel assembly (no starter problem if both were used with 6 volt starter). You might want to get the flywheel resurfaced (about $40 at NAPA or other machine shop). If the clutch disc and pressure plate surfaces look good, you could take a chance with them. Same with the throwout bearing and the crankshaft pilot bushing.

But, if you want to play it safe (I would), a full clutch kit costs $150-200 and it would include a clutch disc, pressure plate, throwout bearing, pilot bushing, and clutch disk alignment tool.

You are correct about the 4-speed being a simpler shift mechanism compared to a 3-speed. You will most likly find that you will hardly ever use 1st gear (but, so what). The four speed can be a little uncomfortable if you want three people in the front seat.

Tim