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Forester transmission fluid change

There is an interesting thread going on Forester forum.

Subaru claims that CVT fluid is a lifetime fluid but most of us got a note from Subaru that the transmission warranty is extended to 10 years or 100,000 miles whatever comes first. The dealership parrots this tune and is not in favor of changing the transmission fluid. That sounds very fishy to me. I feel, thats an indication that these transmissions are going to fail little after 10 years.

I wonder what one can do if the dealership refuses to change the fluid? Do ASE certified mechanics have the fancy equipment that Subaru needs to replace transmission fluid? or I should check with ATRA certified mechanic if they would change the CVT fluid?

A brave owner ( changed this fluid himself and it doesn’t look that easy to DIY.

I will be in a pretty much same scene within a year so planning in advance.

Quite a procedure That guy used a total of 18 quarts for the flush and fill. The fluid was in decent shape at 100k, right? So I might start checking with local Subaru specialist shops and see if they’re set up to do this at 100k.

I was planning on getting it changed in the near future. Didn’t know the dealers were refusing… but how can they, as the users manual says change at 25k for severe use, which we all qualify for.

Severe service is any of the following:
driving in the mountains
driving along the coast
driving in a city
driving in the country
driving in the winter.

Is it a catch 22? Don’t change it and have problems, and Subaru says warrantee is out because you didn’t get it changed every 25k ?

Find a transmission specialist.

Exactly. I check every line under severe driving.

Are ATRA certified good enough or there is better than that?

I checked his comments on the board and his 100K are exclusively highway miles. So he could wait till 99,xxx miles. Most of my miles are severe. So according to the guidelines, I am supposed to change every 28-29K, just like the OP of the thread. If our local dealership sings the same tune, then I will have to go through this.

I have no idea… I use a transmission place that’s close to me. And they are a member of ATRA. They are big. And they service most if not all the dealerships within a 20 mile radius. Dealers will send them any transmission that needs to be rebuilt. They know their stuff. 10+ bays…and always filled. And all they work on are transmissions/transaxles/transfer-cases. Nothing else. Been in business for over 40 years.

There is something else to consider with a CVT. The parts essentially all wear into each other which makes them quite hard to rebuild, They are usually just replaced. I have been seeing more “lifetime” fluids which I don’t agree with. The best example are some push mower engines being sold by Briggs and Stratton. Mowers are about as severe of a duty use as you can get and they claim you never need to change the oil!!!

One thing to note re CVTs: highway miles still exercise the CVT. A conventional AT stays in the top gear as you cruise at 65-75 MPH. A CVT changes the ratio whenever you go uphill or downhill, even at a constant 70 MPH. You can see the RPMs move up and down with the hills.

I had my subaru forester transmission fluid changed at 105,000 (2015) purchased in 2014. It required a fancy machine that pulled all of the old fluid out and then replaced the fluid. I’m probably explaining that way too simply. However, my point being is that since that replacement my subaru has been running better ever since that day. Do what you feel is right, and have a certified mechanic replace the fluid. Instead of risking wrecking the transmission by doing it DIY.

Nice video though I think the guy made the work harder than it had to be.

I especially like that he had Alvin and the Chipmunks helping.


The reason that Subaru extended the warranty is because of a defective solenoid in the valve body. The solenoid cannot be easily replaced so they replace the whole valve body. Had mine done already.

Few questions,

  • How many miles do you have and year of the vehicle?
  • Symptoms and/or codes?

@Noelm, 2014 Legacy 2.5. Check engine light at 57k miles. When the check engine light (CEL) comes on in a Subaru, the ABS and BRAKE lights flash to make sure you see the CEL. I don’t remember the exact code but it was in the P16xx range IIRC. This happened a few months before the warranty was extended.

I have never received a notice about the extended warranty and was told that because I have had the valve body replaced, I am not eligible for the extended warranty.

Edit: there were no symptoms other than the CEL and the other flashing lights and the ATF looked like new at that mileage. I have noticed after the valve body change that my gas mileage is slightly lower, I monitor it carefully and record the miles per tank and the amount needed to fill the tank at each fill up. I have also noticed that it is quicker to down-shift, or should I say down-ratio than it was before. It dropped a little more after the charcoal canister and air pump were replaced after I ran through a little puddle of water.

Thanks for the information. Will keep this in the back of my head. Hopefully, never have to use it.