how do you know the pinion depth is correct?
just wondering how you detrmined this?
if you used a measuring tool, or equivalent that is only a place to start from...you need to take a pattern and adjust from there sometimes
The pinion gear will be engraved with a number. This is the depth of the pinion gear from the centerline of the carrier. This measurement must be right. Pinion depth is not to be changed to change the pattern on the gear. When the gears were made this was the depth of the pinion to match the ring to have the gears mesh correctly. If a gear set whines and the depth is right it is pretty much the way it is going to be (as long as it is not bearing whine). I have had some gear sets very quiet and some whine. It is just how the gears were ground. Like mentioned the lower gear sets do/can make more noise than higher gear sets.