Just like any fluid in your car the time will come to replace it, but Subaru did make your life a little easier. With the transmission and differential using a single drain you are about to find out that this is a two for one deal.. when swapping out the transmission fluid your are also removing the diff fluid and vice versa.

After 30k miles this differential and transmission is ready for a new set of fluid.

Subaru guidelines recommend a maximum service interval of 30k miles or 30 months, whichever comes first. If you are driving your car in dirty, dusty conditions or if you are driving your car hard on track or off road, you will be want to expedite this service to keep everything healthy and happy.

Time Frame

This task should take you around fifteen to twenty minutes given how tough it is to get your vehicle off the ground.

Tools

There is one tool we will need to have. and that is the Torx T70 which is used to remove the drain plug. A nice sized 1/2” breaker bar will also come in handy. You will want a good funnel to get that fluid to it’s new home.

Parts

Just a few things in this category today, one would be your 75-90W transmission/differential fluid. Next up is the plug gasket, you can reuse it a few times but it should be replaced after awhile to keep it from dripping out on your floor.

How to

Starting this project off we will head under the hood to locate our dipstick which will be found on the right hand side(passenger side) of the trans. We want to check our fluid level and make sure the dipstick comes out.

Next we will be lifting the vehicle into the air, unless you are lifted and can just slide under it. Now we will locate the T70 drain plug. With your favorite 1/2 ratchet or breaker bar you can now break the drain bolt free. Place your oil bucket below and remove your drain.

As stated above you are draining both the transmission and differential fluid. While the fluid is pour out you can take your drain plug and clean all the metal shavings that have adhered to the magnet. If you are replacing your washer, now is the time to do so.

With all the fluid removed you can place your drain plug back in and tighten it in. Next up is filling up the trans/diff with your fresh fluid. You will need your flexy funnel to be able to get to the fill hole, i.e. the dipstick tube.

Your fill will be around 3.7 quarts, but always double check your specific application. Make sure to take your time and not overfill your transmission. An overfilled transmission can cause the axle seals to start leaking and nobody is looking forward to doing those for absolutely no reason.

Wait a minute or two after you have filled to check fill level… This will give you the most accurate reading on the dipstick. Once you are on the F for full line you should be good to get ready for a short test drive. With your short test drive around your local block you can go back to check for leaks and make sure everything is happy.

Congratulations! You have completed your transmission service! Now you can get back to enjoying your vehicle and putting the