We have a 1975 F-250 RWD Auto with 390. I was going through everything when I noticed the rear section of the driveshaft (past the carrier/center bearing, rear end side) where it slides on it seems to not be on the spines all the way. I can push it up and down like it's barely on the splines. I don't know if this is normal and that is just play, or if it's too short. It seems like as the rear end goes up and down the shaft would need to move in and out, but it seems like it's barely on there to begin with. Maybe some of you can take a peak under your truck? Any advice is appreciated. This is stock suspension by the way.

 

completely normal friend it is around halfway point so its about right to deal with suspension movement not to worry next time you get the chance if i were you i would grease it and probably every other zerk on the truck it helps more than you would imagine

 

That looks okay to me, it looks like it's about half way on the splines.

 

Okay, that makes me feel better. This truck was pretty well abused so I'm going over everything. I will grease it like you said smokenchoken. Thanks both of you.

 

I was worried about the same thing on a long bed 2wd I once owned.. I noticed it when my hanger went out but i was assured it was alright so i fixed it and drove it for years.. I agree you are all good