I’ve been making slow progress on my 73 W100 and got to the point of driving it down the road. I got up to around 20 mph and I get a severe drivetrain vibration. It literally shakes the transfer case lever like crazy. Reading some I see that it might be the driveshafts may not be in parallel.

Looking under the truck the main rear driveshaft is definitely not parallel when looking at the alignment of the yokes. I’m thinking this could be a cause of my issue? Not sure how it could be off-center unless someone pulled the drive shaft and didn’t index the spline when they put it back together?

At any rate if this is something that needs to be corrected I’m guessing I should just replace the u-joints? Any seals I should sway while I’m doing this?

I did check the mounting points and mounting bushings for the transfer case and all looks good there. The front drive shaft yokes all look to be parallel.

One of the pics is upside down but it still shows the difference in yoke orientation.

Thanks in advance.