Rear Axle seals keep blowing what to do?

What up fellow Dually rollers, concrete sleds, slow and lows. Yep I'm a newbie, I have a 1997 c3500 and the rear axle seals keep leaking about a year after repair. they both have been replaced about 3 times, tired of that, should i look into different rear end or what?

Check to see if the diff. breather is plugged up or if the diff. is way overfilled.

Thanks, will check that out.