2014 Tech, 116k, owned since new, maintained per the owner's manual/maintenance minder. While my wife was driving on the highway on a hot day recently, the dashboard light for "A/T temp" came on. She pulled off immediately and let it cool. When I took a look, the fluid was low and a little brown-ish - mostly still pink, no odor.

The transmission fluid change was just about due anyway, so I had that done, along with the TSB for the judder (we had never experienced the judder, so never had it done). I also noticed a slow leak had left some small spots on the garage floor. The shop diagnosed a slow leak in the O-ring connecting the transmission to the transfer case. The O-Ring needed to be ordered, so it hasn't been replaced yet, but that's my plan.

I'm pretty sure the O-ring leak let enough fluid drain so that the temp got a bit high. I'm happy to say that with the new fluid and software update, it shifts very well. The dealer updated the software for $120, so that was well worth the cost. I have not seen the O-ring problem reported before, so mostly I'm putting it on here for documentation purposes. I wish I would have checked the transmission fluid level more regularly, but with smooth shifting since the issue I'm not too worried that the trans was damaged.

Any thoughts?

 

as these vehicles age, rubber seals (o-rings) will start to deteriorate.
you will start to replace more and more rubber seals over time. pretty common as the rubber ages. while; you may be the first one to note the transmission o-ring to the transfer case, just know that it is very common for rubber seals to expand and let air or fluid leak.
pretty common maintenance item to replace - Any o-ring or rubber seal on the vehicle.