When to change CVT fluid?

Hi Bill, As a fellow Forester owner who just got the CVT warranty extension program letter this very week, my advice to any Forester owner is to stick to the manual carefully so you can take advantage of the 100K mileage extension if yours goes bad. Good luck.

this is the most reasonable answer yet; 120K; make sure you buy the best atf SYNTHETIC FLUID available; I’ve got a Mercedes where they said you never need to change the ATF fluid; when trannies started breaking down, Mercedes issued a directive changing their position on that “never change” nonsense. Now they recommend a total flush at 100K. However, remember that there is a problem with changing it if you are a diy person (like me). Its not easy to do as you have to drop the pan and change the tranny filter (yes its important bec those filters can get clogged sometimes). You also have no way to measure the amount needed to be supplied via the intake stick in the engine compartment. As someone earlier suggested, measure the amount removed and refill the trans with the exact same amount. Failure to change the fluid is the main cause for transmission failure. Second, is harsh driving. My wife is able to drive any car and destroy the trans in less than 100K just with jackrabbit starts, slamming it into reverse too soon after coming to a “stop”, etc. etc. That’s why I do 95% of the driving now. Surprise, our transmissions don’t fail anymore. BTW, the owner’s manual in my Mercedes says that jackrabbit starts (in my words ----“punching it when the light turn greens”) should never be resorted to. It doesn’t say why but I know why.

I hear that. My dealer stated they should be changed every 60k miles, but with all the research I’ve done and horror stories I’ve read I’m definitely having mine serviced every 25k to 30k miles. (Nissan Versa, automatic)


30K is what Nissan’s “premium” maintenance schedule suggests

1 Like

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.

MY recommendation is to follow the severe service schedule . . . or “premium” or “service plus” or whatever fanciful name they choose to use

With all due respects, better safe than sorry

Who cares what some lab says . . .

If the transmission fails at a relatively low mileage because you chose to believe the lab tech . . . or the manufacturer’s lifetime fluid propaganda, for that matter . . . YOU are going to be the one holding the bag

And if it fails at a relatively low mileage, BELIEVE me, it will fail outside of new car warranty and power train warranty. And the dealer and manufacturer can point out the fine print and wash their hands of you and the car


again I agree that when possible servicing is the way to go, The key word here is when possible. A large population of Transmissions in the maintance free category are not serviceable by design. In Subaru CVTs there is no prevision engineered in the design to allow for all the fluid to be drained . All that can be done is drain a small amount from the pan and replace it with new fluid. Mixing 5 Qts of clean oil with 10 Qts of used oil is not servicing its robbery. As far as the owners manual recommendations are concerned ours does not match what the actual service manual indicates. I imagine this is the case with other manufactures. The CVT is not the only maintance free system with lifetime lubrication. Your AC system, Wheel bearings, CV joints. Universal joints are all closed systems. Welcome to the next generation of advanced lubrication. Its here and its real. What I find amusing is the one system that does require routine fluid replacement is for the most part ignored . The brake fluid should be monitored and serviced regularly. You would be amazed at the number of owners who have never changed their brake fluid. Will The CVT fail ……You can count on it, Nothing lasts for ever but I believe our Subaru should see 200k with ease.

Does it have an external heat exchanger like most do? Then you can use those lines to do the fluid exchange.

Who the heck have you been listening to . . . ?!

What literature have you been reading . . . ?!

I only partially agree with that

Many u-joints still have zerks

There’s nothing preventing you from doing an ac service . . . recover, evacuate, recharge, add oil as needed. Just because there’s no dipstick or drain plug doesn’t mean they can’t be serviced. I’m a mechanic and service them as needed.

Wheel bearings . . . I don’t know which kind you’re talking about. Tapered roller bearings can certainly be cleaned and regreased. And by the way, this is still an extremely common design in the automotive industry, but mostly on larger vehicles. Cars and light trucks aren’t the the entire spectrum

I believe it was brought up here repeatedly that Subarus with CVTs have a drain plug, which some fast-lube shops misinterpret for the oil drain plug.

I have Nissan with CVT, it also has a drain plug. Total fluid volume is around 9 quarts, drain&refill is few ounces less than 6 quarts, so it’s 65% of fluid exchanged with a simple drain&refill. Doing this every 30K miles is way better than not changing fluid at all and only marginally worse than fluid exchange in oil cooler line or repeated flushing.

Subaru shares Jatco transmission design with Nissan, so likely Subaru exchange ratio is similar, above 50%.


the important thing about your post is that you sold the car at 120K and got a new one. If you’re going to do that, you won’t have it long enough to tell if your trans changes were worthwhile. First, when a person changes the transfluid, they are simultaneously changing the trans filter. Why change it if you don’t change the filter too? The fluid may still have life in it but for how long? I have no question that many, if not most, trans fluids when changed will have life left in it. Changing the filter is just as important as changing the fluid. I would never pay more than $50 a quart for any trans fluid. On my Mercedes, the manufacturer wanted $70 quart for their special trans fluid. However, my research show that they approved $35 Valvoline oil for the same 766.2 trans that they put on tens of thousands of Dodge vehicles when Mercedes owned Chrysler/Dodge. I used the Valvoline @ $35/quart. No problems. Runs like new. Currently @ 144K miles.

Cris seems to be shamelessly promoting his own youtube videos

Isn’t that in violation of the website rules . . . ?

@cdaquila Cris ? Spam?

Two people have clicked the link, and neither of them has flagged the post.

On my screen it says “You flagged this as spam.” in blue lettering

So it would appear at least one person did flag it as spam . . . me

Maybe if you and a few others did the same, it would disappear?

I’m sorrry, but I have a hard time to see any spam it that video. He didn’t even try to sell me something. Maybe he is making a few cents from Youtube - I don’t know, but for some people that video may come in handy.

1 Like