DIY Driveshafts

[Username]

My YJ buildup recently got to the point where I needed driveshafts made. Being the cheap bastard that I am, there was no way I was going to shell out $500 for a set of custom made shafts. So I decided to buy a set of stock cherokee front driveshafts and take them to get shortened and lengthened for my application.

The shafts I picked up were $50 each at the junkyard. They were for a '90 XJ with the 4.0/Auto/NP231 and came with a 1310 CV on one end, a regular 1310 u-joint on the other end, 3" of slip travel, and 2" .120" wall tubing between the slip and u-joint.

After starring at the driveshafts for hours on end I came up with an idea. 2" .120" wall tubing would sleeve pretty nicely with 1.75" tube. I could cut the driveshaft in half and sleeve in X" of 1.75" tube to lengthen the front shaft. For the rear I could simply remove X" of 2" tube and splice it back together with the 1.75" tube. This seems much easier than the conventional way of removing one yoke, shortening the shaft, and reinstalling the yoke.

So out came the calcuator to figure out how thick the 1.75" tube would need to be to equal the strength of the 2" .120" wall tube. IIRC the 1.75" would need a wall thickness of at least .16" to equal the strength. 1.75" .250" wall tube would be approx. 25% stronger than the 2" .120" tube it was replacing.

A concern I had was balancing the shafts once they were made. The more and more I thought about this, the more and more convinced I became that splicing in a uniform piece of tube would have no effect on the balance of the shaft, so long as the radial relationsonship between the yokes is maintained. I still do not know if this is true or not but I'll report back on what I find once the jeep hits the roads.

So I odered 3' of the 1.75" .250 wall tube for $50 online. Once it came, I cut the driveshafts and tube down to length and started to beat in the 1.75" sleeve. The sleeve took a little persuasion to fit inside the 2" tube but it went. Great care was taken to ensure the yokes remained in phase while everything went together. Once the shafts were together I took them to Benny to get welded up and as usual he did a great job. I'll take some pics of the finished shafts and post them soon.

The rear shaft fit like a glove in the Jeep. The front shaft might have some clearence issues with the skid plate so I have not installed it yet. So for $100 for junkyard driveshafts, $50 for tube, and $20 for 1310x1330 ujoints my driveshafts are done. The jeep still needs exhaust before it hits the roads but once it does I'll let you know if the driveshafts are still balanced and how they hold up to 350 ci.

[gnegy]

i did the same for the rear shaft on my YJ, already had a messed up XJ sitting at our shop so it worked perfect.

[Username]

Here's a fuzzy pic of the rear driveshaft, but you can still make out where the sleeve was inserted.