just got a 2015 gs350 with 55k miles--should transmission have flush or fill and drain plus filter? Should transfer case have Toyota 75-85 gear oil or can i use other synthetic 75-90

 

Got detailed response from Tech who gave me a very detailed recommendation: only Toyota fluid drain and fill, dropping pan and cleaning filter, then just drain and fill (no pan drop) again in about 3,000mi if you want to clean even more. Does not recommend flush in my case. Gear oil for transfer case explained can use either Valvoline or other spec rated 75-90 or Toyota75-85
Thanks for info

 

Just drained and filled.