[Shawnski]

I’ve had this since ~ 80k miles. Now at 142k miles and losing up to 4-6 ozs. over 6000 miles. Up to 8 ozs. if I’m racing every week. Ruined my underbody tray but I’ve not bothered to replace it. I take it off during the racing season and reinstall for winter to protect the engine and underbody components. My leak only affects shifting and performance when fluid levels are more than 4 ozs. short. Between me and my mechanic we decided that cost and time to replace the gasket between the transmission halves wasn’t worth it. The engine would have to come out. My plan is to keep up with the fluids, and wait for it to fail (it may never fail under normal conditions if you keep up with it).

 

[Shawnski]

Your pics look like exactly where mine is leaking.

The Mercon LV trans fluid that our cars use turns brown almost immediately after one heat cycle. It looks a lot like motor oil but it doesn’t smell the same. I’d say check your transmission fluid and oil level and depending on which is losing level, you’ll know which it is.

Idk if your 2018 has a transmission dipstick like my 2017 does under the airbox and charge pipe, but if it does you can check it fairly easily. But I hear some later models do not, and then you’re under the car pulling fill plugs on the side of the transmission to check the fluid level. I hope you’ve got the dipstick.