Guys, today i just went outside to do a quick over on the blazer before the trip and uncovered a very scary sight. My transmission fluid is the color and consistency of brand new motor oil. Honey brown and even smells like oil. What the heck is this. The truck is an 01 4wd two door blazer with 195K miles on it. Maintenance schedule has been this

36k miles transmission fluid, M1 synthetic
80k miles transmission fluid, Advance auto brand DEX3
115k miles transmission fluid, M1 Synthetic
165k miles transmission fluid, Valvoline dex6

Now the truck has 195k on it and i figured its a nice day and i would change it, but i think i now have a major problem. The truck has felt very sluggish lately. Not slipping but just not firm shifts. Shifts are very soft and i feel like sometimes when i hit the gas, that all the power is not getting to the ground.
As far as i know, there is no way for foreign fluid to get into a transmission right? Should i just do a couple of flushes or what. Thanks very much for the advice. I should add that during all previous transmission fluid changes, i have changed the filter also and that the fluid has always looked and smelled like good transmission fluid.

 

Keep in mind that your auto trans is cooled by the radiator and with the mileage you have it might be letting cooling get into your trans check your radiator.