05 Turbo? noise

[2stepn]

Wondering if anyone else is experiencing this problem. Had it in the shop and of course nothing could be found.
While pulling my travel trailer up long grades at around 60 mph I have three things taking place if the engine starts to lug at all. First I notice a scraping sound, like sheet metal on a rough surface, I also notice the boost gauge is bouncing back and forth and I notice a slight bucking taking place with the truck.
If traffic will permit I'll force a downshift and the problem is gone.
If I can't do that I'll slow to below 55 and the trans will down shift (If in tow/haul) and that also takes care of the problem. If I don't do either it seems as the problem will continue to occur. Help

05 F250
5500# trailer

[RaulDog]

Sounds exactly like your turbo is over boosting because of being in a bind and the sound you are hearing is the excess boost releasing out your intake which is normal to sound like that but if it is stock (no chip) your turbo should not over boost. May have issue. The down shifting will eliminate problem because of higher rpms. Hope this helps.