OK my 05 mazda3 auto has just over 27k miles and has been shifting hard from 1st to 2nd (found a TSB for that needs to have the ECU updated). So tonight I checked the trans fluid and it was pretty dirty. It didn't smell burnt it just wasn't your typical trans fluid red. At 30k its recommended to change out the trans fluid (which I will have someone do Mazda is way over priced on the 30k service). Should I be worried or is this normal?
Also when changing out the fluid should I stick with oem or put in a syn fluid?