2002 Chevy Silverado Left Front Wheel Bearing (3rd in less

I had my truck in about 1 year ago to fix the anoying rattle in the steering colum, which happened before which is a Chev classic problem. When th deler greased the steerign box they said to grease the shaft that fits intothe wheel bearing, which I did. I noticed at that time the whell bearing was a bit gravely feeling. I changed the bearing shortly after. The replaced bearing failed after 1500 km. The 2nd replaced bearing lasted about the same 1500 Km and failed. I am on my third bearing and once again I am at about 1500 km and yup it is whinning and I jacked it up and yup it is loose and shot.

Whats going on.

The bearings are sealed units. They are held on by three bolts. A monley should be abel to change it.

i am at a loss. There is no presure on the bearing so what the Freek is making them fail.

Thx