pinion nut size?

Very likely your cause!

 

Do you mean the yokes on each individual shaft are out of phase or the propeller shaft and inter axle shaft don't match up? As long as the yoke at each end of each individual shaft are aligned, then the yokes are in phase and is not the source of your vibration.

If you were to align both the propeller shaft and inter axle shaft to each other, the moment you turned a corner or spun a wheel they'd be misaligned again. Just the nature of differentials.

 

I will report back after I give it a thorough look tomorrow. Got my head scratched!

 

For best result you always want the output of the trans too be parallel to the pinion of the differential. A little down on the pinion is better than a little up. The torque of taking off will raise the pinion to be parallel.

 

I have a 3:1 torque multiplier that use with a 3/4" torque wrench.

 

After looking closer at the two shafts I see why they might not be all in a straight line. Looks like a joint was changed and put back together 180 degrees off? Also good idea about the 3:1 multiplier. Are they pretty accurate?

 

It's just gears, so the only thing to make them inaccurate is that they have some torque loss through the gears. But considering the last pinion nut I did has a spec range of 900-1200 ft/lbs, they don't have to be ultra accurate. Using the maximum torque will still get it well within range even if it loses a little.

 

if you take off yoke nuts they should be replaced as they are single use crush type lock nuts

re use they are prone to coming loose

ask me how i know ........after having driveshaft fall out in the toll booth on the george washington bridge