Is there any point to just having the fluid changed in my auto transmission in my Outback or should the filter be done as well?What about the differential fluids?Should they be changed and is it a big deal to have them done?

there's a search function which will address questions like this. your service manual is a good source as well. i believe your transmission has a screw on external filter, replace that. don't bother replacing the internal "filter", it's just a screen and doesn't do much of anything.

 

you didn't mention how many miles?

replace the diff oils with synthetic gear oil.

big deal in what way? it's very simple to do, remove drain plug, drain and refill.

Hi 2000Outback! I have an '00OBW also. I would (and did!) replace the external ATF filter. It's a little pricey OEM, like $25 I think. It has the same thread diameter and pitch as the engine oil filter so I crammed an amsoil eao36 onto mine. I chopped open the OE ATF filter that was on there and it looked like a normal engine oil filter to me, except maybe it didn't have a bypass I don't remember so it might be more of a hydraulic filter.

 

If the ATF hasn't been changed before and it has any normal mileage it wouldn't be the worst idea ever to change it. I'm using the amsoil synthetic atf and it shifts like a dream. You can do the 'pump and dump' method for changing ATF to get more of it out (because you'll only get like half with the drain plug while the rest remains in the torque converter and stuff).

 

The diff oils are definitely due for a change if they've never been changed before (because if it's never been changed you've got all the break in metals in there and there ain't no filter for the gear oil, plus it may have sheared and if gotten hot oxidized). I put amsoil severe gear 75w140 in mine; seems to work great, a little heavy? maybe heavier at operating temperature but i don't care.

 

This 4eat phase II atf does have an internal screen filter, but it's not listed as a replacement item and it doesn't need to be because the external filter is a great idea catching shavings and shreddings before they have a chance to plug up the atf cooler and lines.

 

And be thankful for these luxuries like an atf drain plug, atf dipstick, and external filter - a lot of newer makes don't have any of these!