Final Update, should have reported earlier but there it is. So I now have a new Transfer case and a new rear diff. Problem solved, no more rear end noise or grinding and driving as it should. All covered under warranty. Not sure what was the cause but here's hoping that it stands up to time and mileage. Still love the car.
Use what you like. Either one works well.
I have no idea about new Kia oil. But either way if you use just pay attention in the morning or when the car is cold to see if you hear like a grinding sound. If you hear that after changing the oil switch to a different oil as soon as you can.
Not a whole lot of difference. As the numbers indicate, 75w90 just thins out slightly less at higher temps than 75w85. That is actually a good thing in my book, especially for times when you drive the car hard, like at the track, and the diff temp starts to climb.
Another Stinger came into the dealership with the same issue, diff failed/they replaced, failed again in 1 month! They think it’s the oil, very thin/black/metal shavings after a month of driving. I knew in 24 hours it wasn’t fixed.
hey bud how did the motul hold up ? and did you have to add any extra friction modifier to it ?
Is doing well! I have had zero issues and been running great since I switched over. No I did not add any friction modifiers to the oil.
Motul Gear 300 LS 75W-90. The LS is for limited slip. Thus the additive is already in it.
Probably should had clarify with the person that asked but just figured they knew.
i think it calls for the atf 6 from motul
