Internal Transmission Filter Change

Author: Chiketkd

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On a scale of 1-10, difficulty level of this job is about a 4, and surprisingly only two main tools are needed: 17mm wrench and 10mm socket w/ extension. Allocate about 3 hours to do this job.

In terms of parts, besides 7-8 quarts of ATF, you'll need a container to drain the old ATF into. You will also need a transmission pan gasket (Subaru Pt #31397AA040) along with the internal transmission filter (Subaru Pt #31728AA011). Advanced Auto Parts sells a kit which has a filter and gasket for $29.98. The part number is shown above. There are two different ones, and you'll need the one that has a 'curved shape' around the circular opening that goes up into the transmission. This 'curve' gives the appropriate room to the solid metal tube. The other filter kit is more rectangular in this area and bumps against the tube.

Start by jacking your SVX up on the passenger side and place a jack stand under a reinforced part of the frame before going underneath to undo the transmission drain plug with a 17mm wrench. You may want to jack up both sides for better access.

Once that's done, use the 10mm socket on an extension to undo the 20 bolts that hold the transmission pan in place. The pan should drop down very easily, but if not, use a thin pen knife blade to gently pry the pan off. More ATF will drip down once the pan is removed.

Take the pan and clean the inside very thoroughly with a rag. You'll now be able to look up and see this (The stock ATF filter is the dark 'L' shaped object in the bottom right-hand side of the picture):

To remove the filter, you'll need to loosen the 4 gold 10mm bolts holding it in place. The filter won't drop out as there's a dark metal tube that runs across one side of the filter. This tube is held in place with 2 black 10mm bolts which will need to be removed as well. The tube can be hard to remove once the bolts are undone, but a gentle tug will soon break it loose.

Here's a picture of the removed metal tube next to the old ATF filter. Notice the very visible black grime coating screen on the inside of the old filter.

Now, take the new filter and install it, and be sure to use the new rubber o-ring provided that goes around the circular opening that goes up into the transmission.

The metal tube can now be reinstalled and bolted into place. (Note: All the 10mm bolts around the internal filter/tube as well as the ones that hold the pan in place should be tightened only to 8-10 ft-lbs).

With everything bolted back in place, put the new gasket around the cleaned transmission pan and bolt it back onto the bottom of the transmission. Be sure to put the drain plug back in as well.

After adding a couple quarts of ATF (through the dipstick hole - use appropriate sized funnel), start the car up. You should then add the remainder of the ATF while your transmission is in gear. Use the ATF dipstick to determine when the correct level is reached.

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