Constant failure of left side CV joint, 5 times in 3 months

Plymouth Voyager 1992 215,000 miles.
in 3 months this vehicle has eaten up 5 CV joints, all the driver side. Twice when test driving immediately after replacement with new axle assembly. The auto repair shop is stumped as to the cause. I believe it also has bad struts since it bottoms out on even small bumps at high speeds >45 mph. Ball joints and tie rod ends are tight and engine/trans mounts were just replaced after the first 2 cv joints failed. It is not being used under extreme road conditions and has broken each time while in a turn at <5 mph. Last week the CV joint/axle sheared off 2 inches past the spline end while taking off from an intersection, It was replaced again and failed the same day on level asphalt in front of the repair shop with the mechanic at the wheel, just taking off with wheels turned to the left. Replaced the axle last week with a brand new one (I went and got it myself to make sure they weren't using recycled parts) It was installed and ran wonderfull for 8 miles and the CV blew apart again just as I got to my driveway. It is still setting in the street waiting to be towed. Next axle assembly will be #6 since late September. :X Until this all started it had been a very dependable vehicle.