Axle Dump & Axle Seals

I was told by my mechanic that an axle dump will lead to premature axle seal failure. I realize there is a lot of heat down there, but I wouldn't think it would drastically wear down a seal unless it was blowing directly on the axle. How many of you have axle dumps and haven't had any problems? I just got mine cut off today for aesthetics.

 

No problems here. I don't see how it could cause a seal to go bad.

 

That's exactly what I was thinking. He said the heat from the exhaust would make the seal go bad over several thousand miles. I don't see how it would cause such unless the exhaust was directly blowing on the axle.