Dave; glad they fixed you up. Yeah, the driven gear just slips into the housing on the outside of the T5.
There was a big confab on the NWC gear oil/tranny fluid question about a month ago. The conclusion was: not all NWC's use gear oil. I went to the local library, pulled the owners manual for a '89 S-10 p.u. (my T5 decodes to this donor vehicle) and it says right in there to use Dexron II. I think some of the earlier T5's used gear oil.