Re: 30k maintenance - 2018 Subaru Outback 2.5 Limited I changed the front and rear diff fluid recently using mobile1 75w90. I put the car on jack stands and leveled front to back and left to right. The rear was simple and there was improvement in MPG afterwards. The fluid That came out was dark and the magnet plug had gunk on it and the fluid smelled of the tell tale differential fluid smell. The front was a little different experience, first the fill plug was torqued in so tight that I rounded out the 8mm hex plug trying to remove it so went with the "backdoor fill option using the check plug hole and a hand pump to fill. The fluid that came out was also dark but had a red tinge to it and smelled strongly of transmission fluid. After draining and refilling the fluid the MPG dropped significantly. My question is two parts, could the MPG drop be due to over or under filling and why the reddish tinge and tranny fluid smell of the old fluid? Update - took it to the dealer ($500 to get the rounded fill plug out) they drained and refilled the front diff and said they could find no contamination and that CVT fluid for 2018 outback is green and smells more like hoppy beer than tranny fluid. Also that it is impossible for the front diff and CVT to cross fluids on this version of the CVT and that likely it was a break in fluid in the front diff. They disconnected the battery to get the computer to relearn emissions and sent me on my way. MPG seems fine now. Lesson, be very careful removing the front diff fill plug!
I love a good DIY failure story...reminds me of when I was young. This is why I always went to the dealer for diff fluid changes. Sorry new guy, but it happens to all of us. It seems that you took it fairly well.
