CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

2003 Subaru Outback - Fluid in a manual?

Is there fluid involved in a manual transmission

Yes…(10 character minimum).

Yes. It’s frequently called “gear oil.” Here’s more information: https://www.pennzoil.com/en_us/products/other-oils-fluids-fuel/manual-transmission-fluids-axle-oils.html

Yes. Owners manual gives the specs. Some use a version of motor oil, others use automatic transmission fluid, etc., etc.

Except in a Subaru automatic transmission which uses both ATF and gear oil. ATF for the auto trans part of it and gear oil for the final drive. They are kept separated by a number of seals.

That is why it is important with an automatic to check fluid levels now and then. At times the seals fail and gear oil migrates slowly from the final drive to the auto trans. Left unattended and ignored eventually there will be a catastrophic bang and the transmission becomes scrap metal.
The end result is the same as someone botching an engine oil change by mistakenly draining the final drive of the transmission. It’s just that one is faster than the other…

OP has a manual transmission.

My 87 Plymouth Horizon, automatic, had ATF in the transmission and also in the differential section even though the sections were sealed off from each other,

I developed a leak from the differential section and the very good local transmission shop fixed it for not very much money and put regular differential oil in it.

The owner said that Chrysler had changed to the ATF in the final drive for fuel economy reasons and my differential had started making a bare;y discernible whine that the heavier oil eliminated.

I’m fully aware the OP has a manual trans. It’s been suggested a number of times that it may use ATF. That will never work. The transmission is technically a transaxle. The design is near dead on to an old VW Beetle. Both have ring and pinion gears. ATF may lube a manual trans but will not lube a ring and pinion gear set very well.

If ATF were used in a Subaru manual transaxle the gear gnash would likely be insufferable. Hypoid oil is the only thing keeping them from doing it now.The synchronizer ring fit on the gear cones leaves a bit to be desired.

Check the specs for your 2003, but in my 2006 and 2008 Outbacks I use 75W-90NS gear oil. The NS part is important because regular 75W-90 is too slippery and can cause problems. It’s not that difficult to change the gear oil. The hardest part is having the right Torx T70 socket and making sure you have a new gasket. The fill hole is on the rear of the engine.

1 Like