I have known for a while my front driveshaft needed service.
You could feel the slightest of vibrations at freeway speeds and if
you physically yanked on it you can feel/see just a wee bit of play.
There was the smallest of play between the male and female telescoping splines.
I found the female yoke end on Ebay for some crazy cheap money
months ago. Last week I took it and the driveshaft to
Powertrain Industries
in Whitter, CA and they supplied and installed a new male 16 spline end
and took my female end and my U-Joints and balanced it all for $320.00.
I gave them some 383 green and they used that. Came out sweet.
I mention this because he told me he gets a lot of Military driveshafts
to restore, and they do a lot of Shipping and Receiving of driveshafts
from all over the country. It is a pro outfit, prices are right, quality work.
I also mention this because it was a biotch to find a driveshaft repair
company that would even look at large truck parts. If you use them tell
Adrian "Artisan" the plumber sent you.
PS, the front driveshaft on an M916 is 3.5" in diameter, NOT 4".
I saved the old male and female ends, they are good for a truck
used at low speeds for sure or someone who does not care.
I'll probably throw them on ebay. To buy them would be
about $600 I do believe.
My M916 is close to perfect now.
Someday I will find a straight front bumper for cheap and close.