I am going to change my MTtrans oil to synthetic, and I got under the car yesterday (04 WRX sedan) and it looks like the drain plug for the trans is a big ass torx bolt. I don't have a torx that big, and I am wondering if it is the right bolt to take out before I go buy a torx bit. Also, if that is the right one, what size is it so I don't have to buy a whole torx set, since this is about the biggest job I will attempt on this car. Thanks a lot.

The drain plug is right behind the cross member jack brace. I think its a 21mm socket that works. I have never used a torx wrench ever on the WRX.
The plug may be a 21-22-23mm size.
This is a easy job to do.
Greg Downing

Awesome. I didnt think that Torx was it, its really big. I guess I'll look harder today.

A 13/16" (common spark plug socket size) will fit.

Last I heard the 04s did go to torx. But hey, I own an 03 so I don't know for sure.

http://forums.nasioc.com/forums/showthread.php?t=580978&highlight=torx
for one other thread.

Purchase a shop manual if you can. If you still cannot find the large drain plug at the very bottom of the tranny send me a email to gpd323@earthlink.net and I'll send you a low res picture of the drain plug directly to your home email address.
Also, you pour the new oil in the trans oil dip stick hole. The trans takes 3.7 quarts of GL5 oil.
OT,
I have done my tranny 4 times in the last 50K miles. My (current) tranny mix is Redline synth oil in this mix. 1 qt of 75-90 wt NS, 1 qt of heavyweight shockproof gear oil, 1 qt of lightweight shockproof gearoil, and the rest .7 qt of GL4 MTL (manual trans lubricant). This has been the best mix so far in regards to gear rattle, cold weather shifting and my difficult to get into 1st gear on a roll.
Good luck and if you have other trans oil questions, please use the search function on the forums. This has been talked about since the earth was born!
Greg Downing

the 2004's have a torx drain plug?
Ok, then I am sorry. I did not know that. I have a 2002 WRX.
Good luck.
Greg D

Ok Im getting a T70 Torx bit. I looked again and there is no other bolts on the bottom of the trans that could be it. This big Torx is at the lowest point of the trans and I can see the copperish looking gasket so it must be it. At any rate, Im sure Subaru is making it like this to prevent people from doing exaclty what I am doing, which is do your own maitenence. The amount of people that would just put in some ATF or some other random stuff and mess up the trans is probably to much to risk over just making other people a little angry about having to buy a big ass Torx bit.

The amount of people that would just put in some ATF or some other random stuff and mess up the trans is probably to much to risk over just making other people a little angry about having to buy a big ass Torx bit.

Yep!

I ordered one from the Tool Source (in the above linked thread). They have a minimum order charge of $5 though, so you'll need to get something else too.

-Dennis

Yep!

I ordered one from the Tool Source (in the above linked thread). They have a minimum order charge of $5 though, so you'll need to get something else too.

-Dennis


Which part did you order? The only T70 bits I see at Tool Source are more than $20, let alone $5...

Manufactures had to do the same thing with ball joints because the grease spec was for a Moly based grease and dealers/service stations were using 25 cent a tube cheapO grease. The result was too much waranty work because of wore-out ball joints so no more grease fittings.

I used a socket on my 04. where did you see a Torx bit? I never even saw anything that looked remotly close to a Torx bit.

after reading the link above, i see that maybe they changed it mid year. my car was a jan '03 car.