CVT Drain and fill

[MoleMan]

Some advice is needed here.

 

Since the warm weather is upon us now I generally do maintenance on all my vehicles during the summer months that would be hard to do in the winter.

 

My 2018 3.6 has just under 20k on it. Very rarely driven in fact the car has been driven 130 miles since last year. Would it be better for the dealer to service the CVT trans fluid or an independent shop?

 

I just remember on one of my Toyota’s it was a real hassle to do this service and it was better off done by a dealership.

 

Any advice would be great. I know the interval from Subaru is 30k however I figured while I was changing the oil etc it may be best to stay on a semi normal maintenance schedule.

 

Thanks.

[ammcinnis]

I know the interval from Subaru is 30k ...

That 30k CVT "service" is an external inspection for leaks only, per Subaru. You can do that yourself.

[donglow2]

MoleMan,

You must be outside of the U.S. for it to says change the CVT fluid every 30k? The biggest problem with Subaru USA is they say the fluid is lifetime. Visible outside inspections due nothing but tell you if it is leaking which would be extremely rare. The valve body of a Subaru CVT cannot handle dirty fluid with break-in metal shavings and will usually go out past the 60k warranty. This is why the resale value of USA Subaru drops significantly in the USA. My first one went out at 67k, but it is hard to stay too mad at Subaru USA because they did send me a check for the whole $3,800 the dealer charged me about 3 months after, without my saying anything.

 

Now to your vehicle, transmissions are very different than engine oil. Engine oil gets dirty by combustion. Fire, explosion, etc.. Junk gets past the rings and the valves and into the engine oil passages. The fluid in the transmission only gets dirty by wear, not combustion. The good mechanics in the USA say to change the fluid every 60k so 20k is not much, but a lot of good mechanics recommend the first one be earlier so you are fine having it changed now.

The Subaru CVT fluid is much easier than about 2012 and up Toyota (CVT or Automatics) that use a straw drain level check. Besides the crazy straw the Toyota transmission temperature range you have to use to get the level correct is very low which causes the time period you have to do everything to be very short until it is too hot, then you have to wait hours for it to cool down. A real pain in the ass.

 

Subaru uses a standard level check plug and higher temperature range. Plus unlike the newer Toyotas Subaru have pans so a temperature gun works pretty well if you don't have scan tool that reads transmission temp. You just keep adding fluid until it starts pouring out and put the plug back. I have done it on three Subarus and it seems like the level isn't nearly as critical as the Toyota. A 1/4 of a quart on a Toyota can be the difference of too low or too high.

 

I have only done 4 cylinder Subarus that use the 580 transmissions. Your's uses the 690 transmission so I am not familiar with where the drain, fill, and level check plugs are. Do a youtube search. For a 4 cylinder with a TR580 this is the best video

. This guy gives great instruction!

 

One important thing I highly advise before you try to replace your own fluid or do any major repairs is a hex set socket bit set with special extra bitting grips. If you watch Mr. Subaru lay his tools out this is what he uses, but he never tells you what it is. Mine is the Proto which is a cheaper knock off to the original one that costs 3 times more. I got mine here https://www.grainger.com/product/56JT06?RIID=61942776435&GID=&mid=OrderConfirmation&rfe=0b8f2a71a2c53eb9ba1f8dda9f8ec34deeb4da43c04d24a3017a3f034f784450&gcrfe=0b8f2a71a2c53eb9ba1f8dda9f8ec34deeb4da43c04d24a3017a3f034f784450&gucid=EMT:10339122:Item:CSM-323&emcid=NA:Item . It is very easy to strip a hex/allen subaru bolt and some of the ones on the tranmission require long extensions to get to. If you strip it there you will be out a pretty penny taking the car apart to access it.

 

Lastly, you need to decide exactly what you want to do. Drop the pain to clean the magnets and get more fluid and grime out, drain and fill, or flush. This is regardless if you do it yourself or have a mechanic do it, but a mechanic might limit your options. Subaru uses RTV as the gasket and it can be a pain to break the pan away. They sell a nice pan gasket if you want to put it back without the RTV. I assume they put the RTV on before they add fluid to it at the factory to keep the fluid from causing seal gasket adhesive problems. You can do or have done drain and fill or flush with or without dropping the pan. Drain and fill only replaces about 35% of the fluid whereas flush replaces all, but is more time-consuming and difficult. One last thing, CVT fluid stinks so put plastic down and expect to wash rags or dirty clothes multiple times.

Edited March 31, 2022 by donglow2

[Brisvegas]

 

Thanks for the very interesting and detailed post donglow. The CVT fluid change debate is a subject that always attracts my interest. I have searched online extensively and have yet to find a reputable professional transmission mechanic/technician who believes in "lifetime" tranny fluid.

[Max Capacity]

See post #18 ,

 

https://legacygt.com/forums/showthread.php/reputable-subaru-shops-you-would-take-your-car-287758.html

 

PM him for advice.

 

Our 3.6R has 25,000 miles I will have my local transmission take a look at it when it's time. He's a lot less $$$ then a stealership.

 

There is a ton of info on the outback forum or this one.

[Brisvegas]

See post #18 , https://legacygt.com/forums/showthread.php/reputable-subaru-shops-you-would-take-your-car-287758.htmlPM him for advice. Our 3.6R has 25,000 miles I will have my local transmission take a look at it when it's time. He's a lot less $$$ then a stealership.There is a ton of info on the outback forum or this one.

 

That's a great post by that JMP guy .... and thanks to you for bringing it up.

 

Living in Australia means it can't help me personally, but it is a great idea. I'd like to see it happen here as well.

[Max Capacity]

That's a great post by that JMP guy .... and thanks to you for bringing it up.

 

Living in Australia means it can't help me personally, but it is a great idea. I'd like to see it happen here as well.

 

cardoc, replied to my PM quickly. So I'd recommend you contact him.