DIY: Transmission Fluid Change

[just4747]

Yeah I was on a level surface before I filled the tranny. And I only drove it after I got impatient waiting for the new oil to hopefully settle. Before that, when I was checking the level constantly, the engine was mostly cool already.

I'm kind of worried about why it was showing as full with only 3 new qts.
I'll check it again once cool tonight.

???

[Sasquatch]

Wait for tomorrow. That oil is quite thick. You could also email the transmission shop I just posted up. They know Subaru transmissions better than most anyone.

I always change the rear differential fluid when I do the transmission. I start draining the transmission first, then move onto the differential to completion allowing the transmission to drain for that entire time.

[just4747]

Yeah, I'll wait again and check a little later. I'll keep that shop in mind just in case.

For you guys that said you overfilled before, did you mean you had also drained completely, and it overfilled after putting less than 3.7 qts. in like me??

Also, I only did the tranny, not the rear diff.

[Sasquatch]

For you guys that said you overfilled before, did you mean you had also drained completely, and it overfilled after putting less than 3.7 qts. in like me??

Also, I only did the tranny, not the rear diff.

Overfill? Yes, drained completely as described. The first time I put nearly the entire 3.7 in which way overfilled it. This time I carefully measured 3.5 and it was still slightly overfull. Next time I'll put 3.0 and add from there.

I'm at a loss as to why 3.0 filled your gearbox. I have a 2004 as well. Did you take a drive prior to changing the fluid to get it hot so it would flow and drain more easily? I always do.

Change the rear differential fluid if you never have. I've always used Redline 75-90W Synthetic in the rear differential, but any quality 75-90W will do well. Getting the fill level correct is a no brainer - it take less than a quart.

[just4747]

Yeah I had driven earlier to pick up the oil, and it cooled for at least a few hours before I started. Then I only started it again to drive the car up pieces of wood to jack it up. So if it was warm all, only a little. And the oil drained out crazy fast and strong, probably due to the warmth and dip-stick being removed.

[Sasquatch]

Yeah I had driven earlier to pick up the oil, and it cooled for at least a few hours before I started. Then I only started it again to drive the car up pieces of wood to jack it up. So if it was warm all, only a little. And the oil drained out crazy fast and strong, probably due to the warmth and dip-stick being removed.

I start draining while still hot as I do with engine oil as well. As hot as I can stand it without getting burned. I just pull the dipstick out an inch or so while draining.

Let us know how you make out.

[just4747]

So I checked again just now after a few more hours, everything definitely feels cool to the touch.

Same level on the dip-stick. Basically the level is perfect- right at the fill dot after I poured in 3 quarts exactly.

What is going on???

There seems to be no way there could have been enough old oil left in the case to equal about .7 quarts total. WTF??????

Worried still.

[SD_GR]

What is going on???

Nothing.

I haven't yet measured how much came out, but it is still sitting in a pan. Not sure if I have any thing to measure it with and God I hate the smell lol.

I on the other hand am sure you do have something to measure with. What containers did the gear oil you added to the gearbox come in?

I mean it's strange that its exactly at full after 3 right now.

You likely only removed ~3 or so. Everyone tends to overfill because they don't remove all the gear oil.

If the level on the dipstick is correct, then the level on the dipstick is correct. You can't fix it. Keep on checking it if you are concerned but in general I'd not be concerned. This is what typically happens. I've done this. Many people have done this.

Just check the fluid again a couple times but again, if it's OK, well it's OK.

[just4747]

Thanks. This is what I am leaning towards, as nothing else really makes sense if the boxes are in fact able to hold 3.7qts.

I will keep checking it until I feel safe lol, but if I feel like gettin' dirty again, I will throw the drained oil back into the bottles to see how much it shows. Although those bottles are annoying because the full level of them is always above the highest number/notch on the side, ugh.. but at least I still have the 4th unopened bottle to go by...

[SD_GR]

I've been in your shoes. I added over 3 to mine first time I drained, resulting in overfilling. I think the gear oil is so viscous that not all of it comes out. I mentioned measuring what you removed to try to ease your nerves but ultimately it doesn't matter how much you removed; all that matters is what's in there now. If it's OK, that's that. Enjoy the car, and keep checking until you're sure.

[jamie007]

I'm planning on doing this, this weekend on my 09 WRX. Does anyone know if the instructions are the same, especially regarding what size torx driver I might need?

[jamie007]

Thanks for all the replies!

Anyhow, just changed the tranny oil on my 09 WRX. And yes it does use the T70 bolt for the drain plug. I would highly recommend a breaker bar to break it loose. I got the T70 driver at autozone like someone else mentioned. I also picked up a funnell with a plastic accordian type hose for $3 which saved me removing the intercooler. I put in 3 quarts of the mythical "Extra-S" oil and that put me at the lower mark on the dipstick. I put in another ~1/4 bottle and now I'm in between Low and Full. Going to drive it around today and check the oil again before adding more. Thanks everyone for the helpfull info! Doing this was a snap and saved me $150 that the stealership wanted...

[Meyou3]

Could someone tell me were the transmission fluid dip stick is on my 94 impreza EJ20 turbo? the only thing i found under the intercooler was what i though was the front diff dip stick im not sure though????

[oguitar]

Not sure but I think the front diff and transmission share the same oil.

[nofear6235]

Does any one have part # for 2006 WRX transmission oil plug gasket? You guys get this one from dealer, or other places carry as well?

EDIT:
Today went to the local dealer and got needed part.
So here FYI people.
2006 WRX tranny oil plug gasket part # 803926070.
HTH,
Alex