When to change CVT fluid?

[mikepolitte7520_144010]

This is our third Subaru Forester with the CVT trans and turbo motor. Like the rest of you questions as to servicing the CVT keeps coming up. Like you all have indicated each manufacture has its own requirements. Subaru has several CVT transmissions and two different CVT fluids. One being there standard CVT fluid available in Qts and the High Torque CVT fluid for the turbo motors. The high torque fluid is only available in 5 gallon pails and cost near 500.00 for a pail. Subaru also claims servicing is not required but again in fine print say other wise for harsh conditions. After much research and face time with Subaru engineers and service managers there is universal agreement that leave it alone is the correct action. As it turns out even if you wanted to traditional servicing just is not possible. Again like all of you I was not satisfied with not servicing the trans and decided to gather the equipment necessary and a pail of fluid and do a modified service. Considering the cost of a trans against the 500.00 pail it seemed worth the effort. My theory was to drain the 5 Qts ,refill, run for 10 min then do it again for a total of 3 times. The is no provisions to flush the trans like other cars. It was my plan to change the fluid at 50k. Now here is ware it got interesting. I have my engine oil tested at each change at a lab. Trend analysis has proven extremely valuable in determining engine condition. On our 2016 XT I also drew a small sample from the trans when new to establish a base line. Got the results and filed the results away. As we approached 50 K I again drew a sample and sent it off. Surprise almost no change with a conclusion suitable for continued use. This kind of took the wind out of my sail and decided to wait until 100k to service. Well 100k came and again set the sample of and the same thing happened. No need to change. Wife is not happy considering I have a expensive pail of fluid and no idea if its needed. Living in the mountains of WV with its harsh winters and hot summers this CVT has not had a easy life and yet not a single problem. We finally traded up at 120k for a new 2018 XT touring and currently approaching 40k and have no plans to service the trans. My recommendation for any one with a CVT is to have the fluid checked at a lab before spending your life savings on a unneeded service. Talking to the lab techs it seems these next generation synthetic fluids are the real deal . I have no exception that there will be no future problem with the trans but I am convinced that changing good oil is not going to prevent them either. Maintance free is not mean trouble free.