SORRY...just noticed there is a general tech area, so I posted this in that one....delete this one at will moderator...thanks

The vehicle is a '93 Concorde 3.5L. The pass side halfshaft seems loose where the CV goes into the trans output shaft spline. When I jacked the car up and rotate the wheel back and forth, I can physically see the CV joint move up and down some where it slides over the spline.
Will this last a while the way it is?
When I put the car in reverse and step on the pedal pretty hard it makes a clunk so I think this is where the noise is coming from as all of the motor/trans mounts seem tight and OK. It doesn't make any vibration or noise when driving at any speeds though, and there is no leak at the trans output shafts.

Thanks for your opinions