"B" drive shaft in "A" torque tube for F150
 

I'm doing a F150 transmission conversion and I have to shorten my "A" drive shaft. Then I got the idea, why not just cut and weld a "B"drive shaft. Is the "B" shaft superior compared to an "A" because of it's larger diameter main tube? Any reason why it wouldn't work? What do yall think? Thanks.

Re: "B" drive shaft in "A" torque tube for F150
 

You will have to shorten the torque tube as well as the drive shaft, and the radius rods. I don't think there was any welding done on the drive shaft itself.

Re: "B" drive shaft in "A" torque tube for F150
 

On the drive shaft you cut it and mill a new spline on it. It is not a big deal. I would not cut it and weld it. I see no reason to use a B. I have run flat Head V8's with the Model A rear axle. I have a pickup and Roadster that way now with the F150 4 speed.

Re: "B" drive shaft in "A" torque tube for F150
 

Welding on the Drive Shaft WILL warp it. Then you will have to spend mountains of time trying to straighten it back out. Even couple thou warp - out of straight - will make it vibrate. Don't recommend welding. Been there and done that and wont do it agin.

As George said "mill new splines". You can mill the new splines using the old ones as guide -- THEN - cut to length. If you cut first you loose the centering dimple in the end of the shaft.

Re: "B" drive shaft in "A" torque tube for F150
 

I think your right many a's have a straight taper torque tube the larger driveshaft wont fit inside

Re: "B" drive shaft in "A" torque tube for F150
 

Good points about warpage from welding and that the B shaft won't fit in a A torque tube. So, I'll machine and shorten the A drive shaft. Thanks to all for setting me straight with my bad idea!

Re: "B" drive shaft in "A" torque tube for F150
 

A pal in the Club had splines milled in the A shaft and shortened to fit. Runs it open with a U strap to catch it if thing go wrong. You really do not want a shaft to hit the road at speed.

Re: "B" drive shaft in "A" torque tube for F150
 

When you start shortening the Torque Tube - just remember. Torque Tubes are not perfectly round on the outside. Most are egg shaped, which makes it difficult to line up once the short piece is removed from the length. It is the centerline of the TT hat is IMPORTANT to keep purrfekly straight and the Flange (the part with the 6 bolt holes) puurrfekly square with the centerline. ken