I would remove the air box and the upper/lower radiator shroud for access and inspection of the entire oil cooler line setup. Drivers side of the radiator is the oil cooler lines, which typically leak at a crimp connection to the rubber hose part - but I suppose an o-ring would be possible. Yes, there is an o-ring and clip for attachment of the line to the radiator, but good luck finding the o-ring by itself. I suppose you could take the internal o-ring out of the connector and match it up - but be sure the o-rings you buy will last when exposed to engine oil and don't get any debris in the oil cooler lines. Be careful to not lose or damage the retaining clips if you intend to re-use them.

If you want to buy the new fittings which come with all-new O-rings - here you go https://www.dormanproducts.com/gsear...igin=YMM&q=oil cooler connectors. Should be able to order these from your local parts store. Note there are two o-rings on each connector. External o-ring for connection to radiator. Internal o-ring for connection to the line.

If you end up buying oil cooler lines, don't buy the Dorman ones. They are reportedly not very good. I have had very good luck with the AC/Delco ones not leaking for 30K miles so far.

Good luck and best wishes for a successful repair.

 

Ok so this is oil not transmission. Thank you for the help and information.