I had a recent discussion on the wearing of a CV joint.  I devised a 
simple visual aid to assist everyone in understanding the difference 
between flipping an axle over on the same side and switching the axle 
from side to side.

Take a paper towel tube (or similar).  Make an L shape cut in both 
ends of the tube on the top, making a tab.  Bend up the tabs.  You should have a 
tube with a tab poking up on each end of the tube.  Make the cuts at 
the same radial location on the tube.

With you left hand, place your thumb against the tab on the left side.
Make a mark on this side of the tab with a marker, pen, blood from 
your cutting mishap, whatever.  Your left thumb is the transmission 
applying a torque to the CV joint (the tube).

With your right hand curl your index finger around and place is 
against the tab of the tube on the right side.  Make a mark there 
too.  This finger is the wheel resisting the torque applied by the 
transmission.

If all is done properly you should have marks on opposite sides of 
the tabs, when looking at the tube.

The marks indicate the direction of load when accelerating or normal 
driving.

Now, after understanding the loads from the tranny to the wheel.

Flip around the tube, and apply load with the left hand again.
You should see that the load is applied against the SAME location
(your left thumb will be against the mark).  Flipping around an axle 
on the same side of the trans doesn't change the load.

Now, apply load with your right thumb.  This is the same axle, on the 
other SIDE of the tranny.  Resist the load with you left index 
finger.  Both of these  load points will be on the side of the tab 
without the markers.

Summary - To lengthen the life of a CV, one needs to switch sides of 
the transmission.  

Vanagons - For those with autos, you need to remove the CV's 
from the axle and install on the other axle.  Manual trans are the 
same length.  Don't know offhand about loafs.

- Jeff