I have a Toyota 4runner and recently had the transmission pan and all lines replaced as it was sticking in neutral and leaking fluid. When the sticking started it also made the engine louder when idling and a whining sound that gets louder in first gear. When I start to go until about 15 miles in hour it makes a winding sound almost like an electric car "wheeeeee". When I start going faster it seems to subside and just seems a little louder than normal. Just had a friend look at it and he said the sound seems to be coming from the lower wheel the belt wraps around.
Some mechanics have guessed alternator or drive shaft, but I'm not going to pay for them guessing.
Any thoughts and help would be appreciated.
Thanks

 

How many miles does the car have?

I would replace the belt, check the idler pulley, tensioner pulley, etc.