1995 K1500
 

hey guys my pickup is acting up , for the past couple months when gas is applied, and only when gas is applied i have a loud humming noise that smoothes out the faster i go, but doesnt start until i hit 25 mph no matter what gear im in , as soon as i let of the gas it goes away, front cv shafts are good, u joints are good, rear pinion bearing has no play in it. Im stumped, help would be appreciatted

Driveshaft CV ball?

ball? what do you mean ?

Speculations... (since it isn't engine speed or specific-gear dependent)

In addition to Red's suggestion...
Tire wear
Driveshaft out-of-balance
How's the rear diff gear oil?
Have you tried the 4-wheel drive engage/disengage?

Any more info on the problem -- does it do it in neutral, things like that?

RH77

tires are nearly new 33 inch BFG all terrains, with no unusual tire wear , all the weights that were on the shaft are still on , rear diff oil is ful both front and rear, it not in the 4 wheel drive already tested that, somewhere in the tranny on back

How many miles on your truck. Your fuel pump might be going bad.

its not the fuel pump, been checked, its in the driveline , 216,000 on the truck 55,000 on the tranny, tranny flushed 4000 ago, goes in for pitman arm , idler arm , and alignment tommorow

exhaust leak?

lol no , its in the driveline i can feel the humm in my pedal

Put an extra pair of socks on.