Awick,
I think a '46 is the same style as my '41 2 ton fire truck - Art Deco series, they call it. Usually, when someone describes the noise as "whining", they're talking about the transmission. If your truck is original, it probably has the "crash box" 4 speed. The gears are straight cut, and require double clutching to shift smoothly. Straight cut gears are just plain louder, and any pitting or wear only adds to the noise they can make.
Does it get noticeably quieter in 4th gear? 4th is direct, so there's no gear clash in the trans, and it's quiet.
My buddy the former gearbox salesman likes to say "singing gears are happy gears!"
Loud? YES! But also almost indestructible.
By-the-way, the engine noise is ALSO loud on these trucks. Not much insulation between you and the noise-maker under the hood. And, it was undersized for such a large truck, so it has to work pretty hard. As you drive it, you'll learn to distinguish between the engine noise and the tranny.
I hope this helps - keep updating us on your progress - we love hearing about it!
-Michael
