odd drivetrain slop/vibration issue

[black dawg]

I have noticed a lot of drivetrain slop in my burb, that I was blaming on the 10 spline 465/205 coupler. I have also had a vibration that is intermittent. Last nigt I noticed that when the vibration started, that the slop is gone, like absolutely no slop.

The rest of the drivetrain is tight (I have been over it many times).
could the coupler be getting "cocked" somehow, and cause this?

 

[Stomis]

I really doubt it but you could check the adapter for cracks. Thats not uncommon.

 

[black dawg]

Tore it apart today, expecting lots of wear on the sleeve and trans out put. What I found was that some one had replaced the coupler. The coupler has very slight wear, along with some minor wear on the trans output. t-case input looks really good.

The problem was tha the snap rings were not put into the new coupler to keep it from sliding back and forth. With the coupler slid all the way forward, it fits very tight, with it slid all the way back, very very loose. Sometimes driving, it was so sloppy that no matter how hard I tried to be smooth, the driveshaft would bang when shifting. Other times I never noticed the slop.

I put it back together with snap rings and put the slightly worn end of the coupler on the t case input.
Driving, I have to really try to notice the drivetrain slop.
So far no vibration, but I couldnt really see how this would cause the vibration I was noticing, but I guess we will see.