axle problem oin 91 legacy

ok, my mom has a 1991 subaru legacy L, the FWD one. and it eats axles all the time, the boots are always kept in good condition, they dont tear and let dit in at all but the axle still starts clicking and needs to be replace all the time, usually the driver side too, anyone else experience this problem. other than that its a good car.

Have the suspension checked out too, it is a long shot but if there is something in the suspension seriously out of line, it could cause excessive and premature wear of the CV joints.