I know they definitely are not as nice as some of Jesse's, but I made them out of parts I had laying around, and hopefully they will be fine for trail use.

I shortened the old GM 3/4 ton rear shaft by 9.25" by cutting a section out of the middle and welding the two ends back together. I used my Ridgid chop saw to cut it, and was actually quite impressed by how straight the cut was after reading on here about how off a chop saw usually is. I made a jig out of a large piece of angle iron to cradle both halves in before welding, this eway it would force both ends to be exactly parallel. Even in the jig, while rotating one half, the cut stayed perfectly lined up witht the other side. I used the seam inside the shafts to make sure they were welded back in the same position. For the front shaft I had to lengthen the 3/4 ton chevy shaft 6.5", I did this by cutting it in half, and then welding in a 6.5" piece of the same diameter shaft. I did the welding with my stick welder using 7018AC rod.

Front shaft in jig

other end in jig

closeup of a weld

front shaft finished and painted. I haven't munted it yet because I need to get some u-bolt's to mount it with.

you're gonna want some kind of slip spline setup on that front shaft, on hills, and when articulated, it needs to spread, and in some instances collapse, so that's gonna be pushing/pulling on your transfer case with a solid front shaft. also a solid shaft will have lots of stress on your u-joints and yokes.

you're gonna want some kind of slip spline setup on that front shaft, on hills, and when articulated, it needs to spread, and in some instances collapse, so that's gonna be pushing/pulling on your transfer case with a solid front shaft. also a solid shaft will have lots of stress on your u-joints and yokes.

Actually it is a slip spline shaft. I have it fully compressed for painting in the picture. The splined area is where the shaft necks down near the end on the left side of the last pic.

I don't know how well i'd count on that setup holding. IIRC, driveshaft end yokes are fitted into the tube (ie certain size yokes fits inside certain sized tube) then welded, the tube however is a continous piece. simply butt welding two pieces together... seems sketchy to me. when driveshaft shops shorten a driveline, the yoke is remove, amount of tube cut out, and then yoke is placed back on... the difference is taken out of one end, not the center.

also, unless you have a lathe to balance the shaft on, its probably not going to be great for high speed, even with little jig setup you used.


-Rob

I have it fully compressed for painting in the picture.

looks like its also fully compressed in the picture where you have it installed. Once you start putting some weight on that frame and bouncing down the road, you're gonna be bottoming out that shaft.

-Rob

looks like its also fully compressed in the picture where you have it installed. Once you start putting some weight on that frame and bouncing down the road, you're gonna be bottoming out that shaft.

-Rob

Actually the rear shaft (the one installed in photo) is out about 1 inch, but the angle of the photo makes it hard to tell. I used a couple come-alongs to both hoist the frame up in the air (for full droop) and then to compress the springs (as close to full compression as I could get) and surprisingly the length between yokes only varied about 1.5 inches. After looking at it further I think this is because the shackles are at the rear of the springs and are just the right length, so that when the axle moves in its elliptical path, it not only moves down, but also forward about the same amount. The down movement is somewhat counteracted by the forward movement, and the shaft length does not need to change a whole lot.

As for the strength, I think it will hold. The length of the weld is pretty long (the circumferance of the shaft) and consider what it would take to shear laterally (if you unrolled the tube, the force between the two flat sections would be trying to slide in opposite directions, parallel with the weld) a weld of 7018 that wide. I am not am M.E. and don't know the calculations but its gotta be able to handle more torque then the U-joints ever will.

I think my biggest problem is going to be vibration, but it is a trail-only truck, so hopefully it will not be an issue at trail speeds.