For you guys with the NV5600 6-sp manual transmissions there is a filter kit available for your transmission!!!

I found this today looking for the replacement for a customer.
The filter we pulled out was silver but the oil in the unit was golden and "pretty"!!! It looks like it would fit the NV4500's as well.
http://www.genosgarage.com/prodinfo.asp?number=K1444-0060-FLTR%20KIT