I have a 14 900 Crew. I was looking to change all my fluids and purchase a Polaris maintenance kit. My question is why is there AGL, demand drive and angel drive fluids in this kit? I know the AGL is for the tranny but what's the difference between the other two? I was under the impression there were only 3 fluids to change, tranny, front diff and engine? I read something about hub fluid but that doesn't make any sense on the ranger..