Ford F250 7.3L and K&N Air filter question?

[MTGunner]

Hi guys, I normally post in the Suzuki and Tracker forum. I have an '01 F250, 4x4, auto, 7.3L diesel. It is equipped with a K&N air filter and a 4" SS exhaust. These are the only aftermarket upgrades on my truck. I have a friend that just was layed off by the local Ford garage. He tells me that all F series diesels that come in, used, they remove the K&N air filter due to the amount of dirt and grit that is allowed to pass. He tells me that this can prematurely damage the turbo. I, on the other hand, have 118,000+ miles on my truck. It is well out of warranty. I have yet to have any problem with my truck in the turbo dept. The only problem at all has been one universal replacement on the rear of the drive shaft. Is this merely marketing BS from Ford? Any experiences with this problem from anyone? Thanx for the insight and comments!

I've got the same setup on my 02' and had no problems .