The color of a transmission's lubricant tells a HUGE story. Transmission lubricant (regardless of whether it is motor oil, gear oil, or ATF) should never become dark/black. If it does there is a problem. You can bet on it.

 

Or something is wrong with honda choice of putting in z1. it's a 20 year old spec and honda has already given that product its funeral.

 

had a buddy with a huyndai tiburon, he installed brake rotor cooling vents in the rear of the body for looks only, he didn't race. his tranny went and the dealer told him the same thing, so he took it home, removed the vents (bondo'd into the body). took it back to the dealer, and the dumbasses replaced his tranny. dope? yes'm :/

 

Right on the other lubes. I disagree on the motor oil. If you are changing motor oil based on color, you are throwing good oil away.

 

I said transmission lubricant.

I didn't mention motor oil, did I? Wait, I DID mention motor oil, only because it is used in some companies' manual transmissions instead of 80/90W gear oil.

Of course motor oil, in an internal combustion engine, turns dark soon yet still works fine.

 

The Japanese engineers from ATJ and Honda Transmission Manufacturing that I worked with would disagree with you.