[Mstingray75]

Hey guys my dad has a 75 corvette stingray with a th400 transmission. It whines while idling, and shifting into gear. Once he’s driving it doesn’t whine at all. We checked the belts and they don’t make the whining stop. Any ideas on what it could be?

 

[1979Malibu]

A good place to start, assuming you have not done this already, is to remove the pan, clean it and install a new filter. The pump can make this noise when it is starved for fluid or pulling air. It causes cavitation in the pump. I prefer a screen type filter over the "paper" cellulose filter. An explanation for the noise going away while driving is that the fluid gets warm. Warmer fluid can make its way through the clogged filter faster than it does at start up.

 

[chasracer]

I would take it to a trans shop and have them check the pressures on it. Sounds like the pump is going, the whine coming from a low pressure situation. When you drive it the pump is speeding up and increasing the pressure.

 

[south65ss]

I have a '78 Firebird 455 with a th400 and as long as I remember it always whined. It shifts hard and never had any problem. Maybe this is another kind of whine...