How to service Lineartronic CVT

[Zenki]

Hi all, I realize there aren't that many CVT owners on these forums but maybe someone will find this useful.

The Lineartronic CVT is "lifetime-fill". This is technically true; as of current date availability of spare Lineartronic CVTs is questionable at best, and I'm not sure if they require a specialized procedure to reprogram after installation. Therefore the lifetime of the car is probably the same as the lifetime of the CVT.

I feel that it is best to replace the fluid as a preventative measure - at least that way, if it goes it's not because it wasn't maintained. Winger Subaru stocks and sells CVT fluid so they seem to agree with me.

My fluid change was done at 137,000 km. Closer to 100,000 is probably safer. There is no official service interval, because "lifetime-fill".

What you need:

- 10mm hex bit*;

- 8mm hex bit**;

- CVT fluid, approx 5 to 6 litres***

- replacement crush washer for CVT drain plug

- replacement washer for CVT fill plug (optional - it's a solid washer so I didn't replace this);

- pump/syringe/gun to inject new fluid - if it will fill a rear diff, it will fill the CVT.

* fill/check plug, on rear end of transmission

** drain plug, bottom of transmission on black sump pan - do not confuse this with the large Torx plug, that is front differential

*** Winger Subaru sells Motul Multi CVTF in 1 litre bottles. I bought 6 litres but only needed 5. As far as I am aware it is not possible to obtain genuine Subaru Lineartronic CVT fluid.

Procedure:

0.5) (optional but recommended) Warm up the CVT before draining, as this will take forever if you simply leave it idling.

1) Lift the car. Vehicle must be level.

2) Clean area around plugs - you do not want sand or grit in your CVT fluid.

3) Undo fill plug. Leave in place.

4) Remove drain plug, drain CVT. Between 4.5 to 5.5 litres will be drained, depending on CVT temperature. Discard crush washer.

5) Reinstall drain plug with new crush washer.

6) Remove fill plug and fill CVT. Done in the exact same manner as a differential - fluid is pumped in until it overflows through the fill/inspection port.

7) Temporarily reinstall fill plug.

8) Start car. Cycle through transmission positions.

9) When warm, check CVT level with transmission in Park. Add more if required; torque fill plug.

Notes: Motul CVTF cost me ~ $25 incl per litre, trade. The crush washer was ~$3. Don't be cheap and try to reuse it; it'll probably leak and it costs you less than a cup of coffee.

Edited August 22, 2015 by Zenki