Once the axle is out, inspect it for wear. Since the bearing rollers ride right on the axle shaft, it's not uncommon for them to wear a groove in the axle and make it impossible for the seal to keep up with the axle bouncing up and down. Some parts vendors used to sell a bearing with an offset in it so the rollers run on an unworn part of the axle shaft. I'm not sure if that type of bearing is available for the old stovebolt axles or not.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!