Not that I've noticed on my D44 but I have marked them when removed. I suppose it could be out of balance if mounted in a different orientation, but mine is flange mounted so it should always be flat (smooth) no matter what I do. What's the D60 look like?

 

Can't remember how the front shaft is, but 2-piece rear has keyed splines so it can be mounted only in one position.
Went through my picture gallery, but there wasn't any good pics about the front shaft splines, but I'm quite certain that it's not keyed.

 

Same way. I'm talking about the slip yolk part can spin causing it to be out of balance. I have the flange for the transfer case side and straps for the diff. I know I spun the diff side which I think is throwing it out of balance

 

How did the slip yoke spin independently?? It's female splines! Or did you remove it, turn it, and reinstall? Is that your question? I'm confused.

Maybe relevant: a while ago I was looking up any and all info on vibrations since I have a bad one and there is a somewhat common notion out there for early ford superduties that the drive shafts would be the cause of a vibration. The cure was to remove it from the slip yoke into the trans and grease the splines. I'm not even kidding. Food for thought.

 

Not that I am aware of. So far as I know, if the caps on the u-joints line up properly, that's about all you can do.

 

I didn't know they were splined but makes sense. I thought they were like the Jeep's no splines. Has to be the driveshaft as it only happens in 4wd and the vibration gets worse the faster I go
dang I wonder if it's my transfer case then

 

I don't know what's under the boot on my front driveshaft but the only "slip yoke" design I've ever seen is a jaw on one end and female splined hole on the other. I'm still not sure what you accidentally did to turn it. . ?

Remove the driveshaft and go for a spin. Quick way to figure where the vibe is coming from. And don't discount a ujoint somewhere. They can look good but act bad. I agree that the shaft should be true no matter how you mount it.

 

I tested all u joints and I might remove the shaft completely. I can unbolt the straps and just spin the yolk part without the rest of the driveshaft spinning.

 

There is a plastic lining on a male splines, which wears out. Like this:



When that goes, there's a quite a much play, and when enough torque is applied to the 'shaft the splines will jump and eventually destroy them.

 

Well, there you go. Our trucks only can move in 4wd when the plastic splines don't break