2008 Silverado 1500 Whine

[Austin_J12]

I have a 2008 Silverado 1500 4x4 that makes a whining noise when you put it into gear. The truck does not make the noise in park or neutral. When I get to going around 40 mph down the road the noise stops. Truck has 155000 miles on it and the person I bought it from says it has been doing it since 80,000 miles. Any help would be appreciated.

 

[65 sporty]

What does the fluid look like and have you pulled the pan to look for any debris or metal?