I had a TransgoJr installed in my truck about 15K/1 yr ago, the transmission shop builds put Amsoil Torque-Drive (their choice) back in my truck along with internal/external filters. I usually run fluids to spec in my truck but I do like synthetics. Ive been reading on here and have found way too many reviews on what tranny fluid spec/brand people run in their truck, not trying to start a war among Amsoil lovers and haters just haven't seen anybody answer the question I have. Never researched Torque Drive until today when doing some reading and now wondering if I need to keep it in my truck since it's not really approved by GM for my truck. If you already had Torque drive fluid with only 15K on it would you change it out for Dex VI or just keep running it. This stuff wasn't cheap and don't want to spend money thats not needed but don't want to not and maybe cause problems either. I changed the spin on yesterday and had a thin layer of black residue on magnet, I assume that normal. What would you do?