Re: Winding sound at full throttle
When people say "rebuilt" you need to know what exactly they are referring to. Rebuild jobs range from A to Z with parts, cost containment, and mechanic expertise. Personally I will take an OEM in advanced years, well cared for, before even considering a rebuilt. BTDT on both ends consuming and rebuilding!!!!
My personal opinion on your situation is that you have a new gear against an old one; one was replaced and the other wasn't. The old one is "worn in" against the gear it was driving or was driven from; hence the contact surface has a "memory" to it and is not uniform. The new gear has no wear marks so as the worn gear rides on it you get this noise.....quiet spiral gears are one of the mechanical world's marvels, I absolutely assure you. They are absolutely, with a doubt, the marvels of the industrial society in which we live.
So, with that said,if you have some warranty available, work the psayazides out of it before the warranty expires and if you don't wear it in where it quiets down, take it back for a rework.
Mark