The Stovebolt Site Forums The Shop Area The HiPo Shop '46 1/2 ton rearend swap dilemma

I'm quoting from another post.

"Get the center section from the rear end of a 55-62 pickup. Put it in to replace the torque tube type. Then after establishing the correct pinion angle, weld up the pivot's where the axle attaches to the springs."

Will this work on a '46 1/2 ton rearend?

Could I find the chunk from a 3/4 ton '46 (which I believe had open drive at the rearend) and use it if the above won't work?

If you change the chunk do you also had to replace/modify the axles? Also, can someone explain "after establishing the correct pinion angle, weld up the pivot's where the axle attaches to the springs"?

Not sure about the swaps but here's a link to some good info.
http://www.steeda.com/faq/?View=entry&EntryID=14

It doesn't make a lot of since the way its worded does it. If you could just change out the center section, you wouldn't have to weld up the perch pads. If you have to weld the perch pads to the axle house, then you could use any axle you wanted as long as it was the correct width and you wouldn't need a 50's style axle.

I think you will find the 3/4 ton would have a even lower gear or same has what you have, in which case you wouldn't gain much other then a open drive line.

The correct pinion angle is set by locating the pinion angle in relation to the transmission tail shaft angle so the u-joints will work as they should. Since the crankshaft/transmission angle is set, the only variable is the pinion angle. The torque tube has only one u-joint so the pinion angle doesn't come in play as it does with two u-joints. In order for a u-joint to function and last its intended life time, the roller bearings in each cap must turn, and to do that the u-joint angle should be at least 2 and no more then 5 degrees. If the drive line was set with no angle between the output shaft and the input shaft, you could get some strange vibrations and a very short life from the joints.

Hopefully someone with some 40's truck knowledge will come and explain this a little better. Maybe we are missing some information.

Joe

A torque tube rear end only has one universal joint, the one behind the transmission. The mounts where the rear axle tubes bolt to the springs have pivots built in, sort of like door hinges, to allow the rear end housing to move in relation to the springs as the vehicle negotiates bumps or the load on the chassis changes. When the driveline is changed to an open driveshaft type with a u-joint on both ends, the spring mount hinges have to be welded solid to keep the housing from flopping around anywhere it chooses to go as torque is applied to the rear axle. It's necessary to establish the right angle between the pinion flange and the driveshaft before doing the welding. I don't know if the early-style center housing would change out with the enclosed driveline, but if it did, you'd probably have a gear ratio that would pull stumps, and very low highway speeds.
Jerry