As I just replaced the clutch in my 94 Ranger 2.3L manual, I managed to spill some oil out of the transmission in the process. I went out and bought the plug for the output shaft trying to think ahead and ended up spilling it out through the speedo cable hole. LOL. Anyway the oil that spilled out of it turned out to be gear oil.??? I had the transmission installed new in 2005 at a local shop. The transmission label is dated Sept. 2001.
Anyway all the info I could find says use mercon (DexronIII/M). I'm not sure if I should go ahead and drain it and refill it with mercon, or refill it with something like Red Line MT-90 75W90 GL-4 Gear Oil. Would anyone know if refilling it with gear oil is ok. Any input would be appreciated.