F-150 soft axles

Just wondering if anyone else has had this problem. Truck is a 2000 F-150 with 180,000 km. on it. The outer axle bearing spun on the shaft and chewed it down over 1/8". The axle is soft for its entire length and can easily be cut with a file. Axles are normallly flame hardened at the bearing surfaces, aren't they?

Negative. All Ford axles for their cars/light duty trucks are that way. Keeping the rear differential oil changed every 80K or so will extend the bearing/axle life dramatically.