Balancing drive shaft in 2006 Chevrolet Equinox

The axle shaft ROD should be balanced before being inserted into the CV joints and any alteration, addition or subtraction of welded on weights would UNBALANCE the shaft. When one shaft is longer than the other a harmonic counter weight is often mounted on the longer one also. But I have never seen an axle shaft that had been re-balanced from the original factory weights or had a problem with an out of balance FWD drive shaft other than one that was damaged.