You might want to wear boots next time you're at the dealership, sounds like quite a load to me. I doubt the transmission has to relearn anything with a fluid change. Mine will be flushed/changed before cold weather hits, and it won't be by the dealer.

artosa

 

If I remember correctly, the dealer service manual specified a temperature range for the CVT fluid during the change (fluid expands contracts with temp so temp is required for setting fluid level). It also specifies the use of a dealer diagnostic tool. I believe this was to help readout temp.

Transmission service (even a fluid change) is not something I would recommend attempting if you do not know what you are doing. Particularly on a transmission that might be more temperamental like the Subaru CVT.

 

There seems to be a conspiracy afoot to make it sound like flushing the CVT is a event to be supervised by a individual with at least a MS or PhD. I have no college degrees, but I have a well tuned BS detector. The preferred method would be according to Subaru's spec, but having said that, I don't think the CVT will blow up or otherwise cease to function if the fluid level is a couple of ounces above or below the level specified by Subaru. Even some of their own vids show Subarus doing fairly steep inclines/descents to showcase X-Mode. The procedure to flush this CVT seems to be fairly easy, but may be a challenge given I don't have the top secret equipment and knowledge bestowed to me by Subaru.

I do know based on my experience (all of about 110 days) that I don't want stock CVT fluid in my vehicle below 70*F. Synthetic oil and ATF performance in cold (and hot) is superior to most conventional fluids, period. This is my first venture into the deep and mysterious world of the CVT, but I think I might be able to do it (change CVTF) with some patience, research, a shovel and, if need be, my waders.

artosa

 

My point was not that it cannot be done by someone at home. Several on this forum have done it. My point is that if you do not know what you are doing, $450 for a mechanic to do it is a lot cheaper than repairing/replacing a transmission after screwing up a do it yourself job. This is true for most automotive work. That said, $450 does seem steep for the job. I have read posts on forums with Subaru CVT owners paying significantly less than that. A quick search after seeing this thread and I found dealers with service pages quoting $310 or less for the service.

You seem to be suggesting ATF in your CVT. I hope I am misreading what you wrote. Automatic transmission fluid is not the same as CVT Fluid. If you are suggesting ATF in your CVT, then you may want to spend some time educating yourself on the differences between a CVT and traditional automatic transmissions. I would pay particular attention to the parts about fluid needs. CVTs are significantly different than traditional automatics. As a result, they have different fluid requirements. Using ATF in a CVT is known to cause significant damage (things like belt/chain failure) to CVT transmissions.

 

I chose $462 Dealer flush today in Connecticut as we like to pay more to support higher paid auto professionals. The solenoid died and ‘15 Forester at 88,000 will go to my grand daughter in September.

 

My previous experience with synthetics in transmissions was with ATF. I would not attempt to put ATF in a CVT. Amsoil CVTF is what will go in. It's not the question of money, Subaru won't put anything in the CVT that isn't Subaru, and my understanding, and very limited experience is theirs is not synthetic. I'm one of those people who can't leave well-enough alone...

artosa

 

Glad I misread that.

 

I know what needs to be done for the fluid change. I would fill with Subaru fluid at the specified temp range with the engine running. I never heard of a CVT needing a relearn so I was checking here to see if anyone else did. It sounded like BS to me. And I also thought that price was high.

 

It's possible that during the fluid change that the dealership may reflash the CVT programming (depending on the generation of the car and the version of the firmware) and thereby need to 'relearn'. I do know for a fact, that if you remove the power from the ECU, certain settings are lost (ie returned to defaults) and the engine needs to relearn those settings over the next tank of gas or so. Maybe that's what the dealership is talking about - ie. not the CVT but the ECU due to disconnecting of the battery during the service.

 

IIRC there is a built-in fluid life meter. Perhaps they are saying they need to reset that, which might require them to interface with the computer.

 

 

 

Thank you so much. I am non car handy and asked dealer to do it for $460 while they were replacing solenoids ( under warranty) as a precaution due to city driving at 88000 mi on 2015 Sub 15!

 

Yup, that's the one I'm going by. Have the pump, tubing and IR thermometer. When I get the Amsoil CVTF, it will get done.

artosa

 

Don't forget to tape it. I'm sure that the 18+ owners would love to have a video of the event for them to refer to.

 

I have an unused IPhone5 that I think takes video, but I don't have a clue how to post it. It will be a solo event so video probably won't work. Will try to post pictures of the set-up, hopefully not as messy as the Forester vid. Will have a catch can below the inlet and some cardboard underneath the CVT fill point. One gallon water bottles to catch stock fluid and a IR therm to check temp per Subaru, but am wondering if Amsoil has the same expansion rate. Amsoil says to change per SOA protocols, but I don't have Subie's top-secret machinery and procedures. It won't be perfectly level, but will be close.

artosa

 

I have an IR thermometer on hand but don't have OBDII reader. My '14 is due for CVT fluid change.
Where are you pointing the IR thermometer? I'm assuming at the filler plug when oil is running out after cycling P, R, N, D and reverse order?

...a IR therm to check temp per Subaru
artosa

 

That would be correct, getting the temp of the CVT fluid. Going through the gears is done during the flush, not the check.

artosa

 

I'll be doing drain and fill but I wonder if it's a bad idea to put in non-Subaru CVT oil like Valvoline into the mix.

 

If it is a CVT fluid specified for Subaru XV use, you at least have someone to claim damage from if something goes Wong - provided you can prove that you did the right steps in replacing the fluid.

Otherwise, better to stick to the OEM oil.
CVT oils are very special brews.
They need to give friction/adhesion where belt and pulley meet but elsewhere serve as lubricant.

 

Ok, I'll stick with Subaru OEM CVT fluid when drain and fill.

 

Query: Why would the ECU need to be re-flashed for a transmission flush?

artosa

 

I have not done this on our crosstrek as it only has 45,000 km on it...but our ‘11 outback with 212,000 I have done this three times. First time the dealer said it need a relearn...? Since then it has never had the relearn on the other changes...no problems with the tranny.

 

I would have thought a re flash would have been needed when changing fluid but it turns out all you do is change your fluid and go. No ecu programming or re flash needed. I don’t know why the dealer told me that. Don’t I look like the idiot

 

No need to perform AT learning after CVT oil replacement. Here is service manual notes about CVT AT relearn:

CONTINUOUSLY VARIABLE TRANSMISSION(TR580 CROSSTREK) > AT learning
PROCEDURE

• When replacement of TCM, replacement or disassembly of transmission body, replacement of control valve body or Clear AT learning value is executed, perform AT learning mode.
• Do not turn the power of the Subaru Select Monitor OFF during work, and do not disconnect the data link connector.

 

Where is that from? The translation seems a bit off...

 

There is no AT learning step in the service procedure to replace CVTF. Also read the note about when CVTF should be replaced:
CONTINUOUSLY VARIABLE TRANSMISSION(TR580 CROSSTREK) > CVTF
REPLACEMENT

Vehicle components are extremely hot immediately after driving. Be wary of receiving burns from heated parts.

When there is no severe conditions or intrusion of water, etc., replacement of CVTF is unnecessary.

 

Change it every 30K miles. I am currently in a situation where I was never even told it needed to be changed at all and I'm at 111K miles. I now need a whole new transmission and my extended warranty with Endurance is refusing to pay for it because they said it should have been changed every 30k miles. A new Crosstrek transmission in Delaware runs over $12k.

 

Download a call recording app on your phone. Call your local Subaru dealer and ask them how often they recommend you replace CVT fluid. Guaranteeing they don't say every 30k. Call Endurance back and play said recording. If they don't honor it, I'd dispute the charge on your credit card if possible. Unless they can prove it's in their paperwork "you must change tranny fluid every 30k" I would fight them tooth and nail on this.

 

But how does Subaru define the "I"?

 

Perhaps in the service manual? Not the one that comes with the car, the real service manual.

 

Cross limited 2021. my with car manual says 30k( even though stealership still said lifelong) also. Previously lm told that in Japan was 30k, but they dropped that requirement in USA for whatever reason..

 

Why do you want to change the cvt oil? Subaru mechs are saying about every 30000 mi drain and fill. Before I heard that I did it every 60000 and had no problems…

 

First off, you are asking something that happened in 2018
As far as WHY would one want to change any fluid sooner than what is 'recommended' by Subaru ?? Because some feel better preforming their preventative maintenance sooner rather than later. It all depends on how you drive your vehicle, towing, weather, highway miles, more stop and go, short trips, or long trips. All these factors differ from owner to owner. I personally cut all 'recommended' fluid changes in half for my peace of mind. YMMV.

While the CVT may be 'similar' from the 2018 model to todays (2025) model, I'm sure the fluid requirements are different, let alone a few technical/mechanical tweaks that have morphed along the way during manufacturing over the last few years.