The other day when I had the front tires off I was checking my driver side cv joint/half shaft the outer bearing which mates to the wheel hub only had a little play it in,not enough to think it is bad. When i grabbed the housing for the inner tripod joint where it goes into the trans i noticed a significant amount of amount of play up and down and left and right. My question is should this inner joint have play in it,and could this be the cause of my high speed vibration under acceleration. I dont think it matters but when i checked for play the car was in first gear on the jackstands.

 

In theory there should be no play, at the transmission end..

The drive shaft on the drivers side, all things considered, is a pretty easy pull, to check the splines (Don't get me wrong, the splines on the "hub end" are a pain, "if" they're rusted)..

But, if you have a buddy to help, you should be able to check the transmission side without taking the hub apart...

 

Perceivable amounts of play are a tell tale of the joint wearing out. From what you describe, I think you've found the cause of the vibrations. Time for a new axle.

 

Yeah i was thinking it was bad didnt really know still learning about my mini, thank you for responses and I put the Redline MTL and the shaft on order today.

 

There should be around 1mm or less play in the vertical/horizontal axis. Of course it should be able to slide in/out up to several cm in the direction of the length of the axle.