[Lynn Eades]

On a more serious note, the sealing systems were pretty successful. I've never heard of issues with them. This probably transferred to the bushed wheels as well.
By contrast, it was known that a new engine in the desert was toast in about 2000 miles.
My experience has been that the (ball) bearings have been absolutely worn out, or still in good condition (having either been worked to death or laid around for 70 years)