This is strange. Did you mention anything about the drain plug? Any fuzz? Did you strain the used oil to trap any non ferrous particulate.......just in case something is "grinding" in that box? I'm reaching here, but what I've read from your description doesn't sound right.......IMVHO. One other consideration: understand the gearset was clean room clean, but what about the box? Memory says you got that box from Brian after that gut wrenching seal pulling ordeal. Was it equally as clean? Again......just trying help you deduce the most probable causes of how transmission oil gets dirty. And even though that gearset might have been clean room clean, unless you had it apart before you stuffed it in the box, do you know for sure all of the internals were clean room clean as well?
This was a just over 6K oil change (certainly not my norm - but Maggie Valley got in the way

)
All three magnets had almost "0" debris, little enough that I was surprised at how clean they were. I always had chips on the primary before changing the ring and pinion this year.
The gear case was in "like new" condition when I got it, also very surprised there.
As far as the gear set goes. It comes packed in a sealed plastic bag, wet with assembly oil. It certainly looked good enough for me to not do any thing other then just install it.
I'm going to add some lighter oil today (all three holes) warm it up good and then dump it. Putting the Redline back in since I have several quarts sitting on the shelf.
I don't really feel anything bad going on, so I'll finish out the season then then will at least pull the top cover off over the winter.
I have to pull the inner primary anyway to adjust the shifter pawl (stupid design)
This is the Spectro that came with the kit
