totalloser

This worked out so well and fairly easily I thought I'd toss up a thread for anyone else considering this. Cut and paste from my post on single piece driveshaft. Turn your problematic 2 piece into a single piece with a grinder, a welder, and some careful fitup.

Spin the "new" DS on the truck (use brain so you don't die...) and mark with a grease pencil to identify heavy spot on each end. Tack weight on to balance it. Otherwise, here's what I found making my own single piece;

Quote:
I wish I could convey the silly dance I just did! I just buttoned it up and it was not too hard, and I got lucky... well maybe not complete luck, I was pretty careful with the fit up... but it doesn't vibrate and I haven't even balanced it yet!!!

Sooo... Here's the pertinent info; I cut the yokes off my stock rear shaft (diff end) leaving enough tube to grab in the lathe. Cut off the weld and tube to give me the ends to make my one piece. THIS MATERIAL IS TOUGH. I suspect 4130 chromoly steel for the OE shaft. 3.5" OD, but only .083" thick (no, I didn't misplace the decimal) I couldn't find any CM locally in that large, so I rethought it.

The yokes have a machined surface for the 3.5" CM seamless to sit on, but there is also another machined surface further up. Danged if I didn't forget to write down the measurement, but I think it's about 3.560".

So since 3.5" schedule 40 nominal (pipe) erw is 4" outside diameter, and 3.548" ID it makes a very good candidate for a single piece. Easier to weld than thin wall CM tubing, and though about 25 pounds heavier or so, it's a LOT stronger. Not only because of the diameter, but also the thickness, which handily makes up for being weaker than chromoly steel. .226" wall versus .083" wall.

I marked the low points on the yoke to notch out about 1/2" so the weld would be where it should be. If you look at the yoke, you'll see what I mean.

So first yoke centered/tacked. Checked for angle etc and fully welded. Second centered, phased (lined to other yoke) checked, checked and checked again for true-out of phase with the other yoke is BAAAAD. Buzzed it up, used the OE transfer case slipshaft.

I measured the u-joint center at the diff to the slipshaft at the xcase with it pulled back about 1" from the boot on the seal (see note below) and came up with about 70". The yokes sit about 1.75" from the u-joint center to the shoulder the pipe rests against, so I cut the pipe at 66.5" (70"-1.75"-1.75"). I think maybe I could have made it 1/2" longer but I was paranoid that I'd have the slipshaft nail the tailshaft seal during launches due to axlewrap.

Note below: mine's a 241HD, if you don't have the PTO plate you'll probablly just have a seal, so maybe a little more room is good. If my slipshaft hits the boot it's no big deal because it still has a way to go before damaging the seal.

But in short it fixed my problem, and wasn't too hard. Probably entirely possible to skip the lathework and just grind the weld down a bit. Or maybe turn the weld to fit the erw better-self alligning with notch for the erw weld.