Just replaced my tranny with a remanufactured one from satan. When I shift into 4rd and 5th gear, I hear a high pitch whistle sound that increases as I give it gas. Eventually, it seems to go away, but comes back every time I return for 4th or 5th gear. Is this normal with a rebuilt tranny? I've put about 500 miles on it so far.

No this is not normal. Hard to tell whats wrong, there are so many things that can cause this. A roller bearing in 3rd could be bad since they are both just sitting idle on the input shaft while you are in 4th/5th. Could be worn gears that werent replaced.

A reman trans has the main bearing replaced, synchros installed and all other gears checked for wear. Dogs get replaced and most places would install new forks. The actual gear and idler bearing dont get replaced unless they are bad.

Terry

Take it back to them and go for a drive with them so someone actually hears it. That way they can't feed you a line of crap later about nothing being wrong. My .02

They'll want $500 to pull the tranny, and who knows if they've even fix it right once it's off.

I only hear the whistle at low rpm, only when I give it gas.

This may not be the cause of it, but I do have an exhaust leak somewhere near the header/cat. Could that produce a whistle sound only when giving the car gas in 4th/5th?