Just curious....checking the jugs of gear oil I have in the shop has them all listing GL-5, GL-4, GL-3 applications which I run in my 1985 NWC T5. I've only got about 3k since installation, changed it out after 1K, filtered the oil to see if I could detect any metal (couldn't) and the transmission shifts like butter and is quiet. There was some question as to whether Dextron should be used in the NWC transmissions...I chose to go with some advice from a box builder, but he didn't mention the GL-4 info. You mentioned the Pennzoil Gear Plus 80-90....did you find any other manufacturer brands that you might recommend? Is the Pennzoil available in most FLAPS? If it's readily available, I might just drain and filter again and transition to the GL-4. Thanks for the info.
Dave
