Subaru Legacy Forums

Subaru Legacy Forums (
-   Detailing, Maintenance, and Long-term care (
-   -   Pictoral Guide to Changing Transmission and Rear Diff Fluids- 5MT 05+ Legacy GT (

Inigo Montoya 08-24-2008 09:55 PM

Pictoral Guide to Changing Transmission and Rear Diff Fluids- 5MT 05+ Legacy GT
This post will be the full guide for all of you out there with 5MT 05+ Legacy GT/Outback XTs.

The job itself is pretty simple, and should take you about an hour if you are not rushing.

I would give this a difficulty of 1.5 stars out of 5, only because of finding all the supplies.

Tools and Supplies:

1 T70 Torx Bit (eBayed mine)
1 1/2" Ratchet
2 short 1/2" extensions for the ratchet
Screwdriver for the pop-its on the engine cover
Drain Pan
Jackstands and ramps to get the car at level when up in the air
Fluid Pump for the rear end
Funnel and 3/8" inner diameter clear vinyl tubing
Lots of paper towels

I used:
4 QT Redline 75W90NS for the Front Transmission
1 QT Redline 75W90 Gear Oil for the Rear End

But other options exist

Thanks to PSUcaptiankickass for these next numbers:

Oil Drain Plug: 33 ft-lb
Transmission Drain Plug (T70): 50.6 ft-lb
Now the Rear Diff is different depending on what car you have. (This info comes from the 2005 service manual as well, keep in mind)
Legacy 2.5 L Non-Turbo
MT has the T-type Diff: 36.2 ft-lb (both Drain and Filler Plugs)
AT has the VA1-type Diff: 25.3 ft-lb (both Drain and Filler Plugs)
Legacy 2.5 L Turbo
MT has the T-type Diff: 36.2 ft-lb (both Drain and Filler Plugs)
AT has the VA2-type Diff: 21.4 ft-lb (both Drain and Filler Plugs)

Outback 2.5 L Non-Turbo, and MT 2.5 L Turbo
has the T-type Diff: 36.2 ft-lb (both Drain and Filler Plugs)
AT 2.5 L Turbo
has the VA2-type Diff: 21.4 ft-lb (both Drain and Filler Plugs)

And capacities:
4AT = 1.2 - 1.4 qt
5AT = 1.4 - 1.6 qt
5MT = 3.7 qt
0.8 qt all models.

Step 1

Turn on the stereo and put on your hat and gloves

Good, This is where I jacked up the car on the front end, the rear I just use the differential itself:

Car in the air:
This car has room for my Dubs I ordered right? :spin:

Get under the front to undo the drain plug, here is where you need the T70 Torx Bit

Its on there tight, but you should be able to get it. Have the pan ready, it does tend to gush towards the passenger side of the car:

Let it drain for awhile, in the mean time clean up the plug, it is magnetic so it should have fine particles on it. This is normal.

All Cleaned Up:

So clean and fast is is blurry.

Reinsert the drain plug, there is a copper crush washer here you can replace. I did not do that with no ill effects so far, but it is your car, and Subaru does say to replace it.

All clean and re-installed

Inigo Montoya 08-24-2008 09:55 PM

Up Top under the engine bay now.

Remove the engine cover, this means pop-its, I already had my cover off from another project, so sorry no pics of this, there are four pop-its and they love to break off, so be careful. You need a standard phillips screwdriver I believe.

Now look on the passanger side of the engine bay, just where the turbo is mounted.

I have no heatshield after going stage 2, so it may be a bit more hidden for you.

A bit further out:

Now is when you get the funnel and tubing: remove the metal dipstick, and the tubing will actually slide into the fill tube.

Fill with 4 QTs of fluid, the NS version:

Tidy everything up front, you are done. Don't forget to put back in the dipstick.

Inigo Montoya 08-24-2008 09:56 PM

On to the rear diff.

Look under the car, you will see on the rear diff there are two plugs. Looking at the plugs, what size is that? Just having a 1/2 Ratchet works fine, not an exact fit but good enough. The bottom one just use the ratchet by itself, the top one we will need extensions.

Edited: top plug can be done first if you are worried about the plugs being 'frozen' this way you can still have fluid in the diff.

And here is why you cannot do this from straight on, hello exhaust!

OK, now for the bottom one:

This stuff really stinks, so beware:

Here is how I got the top one out:

And comparing the two plugs, Magnet on the bottom FTW!

Ready for fluids good sir!

And this is where the pump comes in handy. I usually pump a bit of fluid into the diff with both plugs out, it can only hold about .7 QT anyway and it can help get out the last of the old fluid.

Then when ready go ahead and re-install the bottom plug and put the pump into the top.

Filling the Diff:

And achieving overflow.

Finally button everything up-

And congratulate yourself, you just save hundreds on your next service by doing the work yourself.

Oh, and be glad that you are not in Arizona in the summer, this is in my garage, in the morning:

RustyShackleford 08-25-2008 01:32 AM

Nice job.

I guess the engine cover you remove in #2 is on top ?
I can't see any reason to remove the bottom engine cover,
and my N/A has no top engine cover. It's a turbo thing only ?

Inigo Montoya 08-25-2008 06:40 AM

Correct, the GT cars have a plastic engine cover, the NAs do not, but I am not sure if the placement for everything else is the same. For NA Legacies and Outbacks I would consult your manual.

srgdrum 08-25-2008 08:49 AM

Thanks! Wow your rear diff oil looked odd?

Inigo Montoya 08-25-2008 08:58 AM

The flash did that, I also think I have a leak on one of the axles and the fluid got contaminated, so it was a weird grey/green color. I am starting up another thread about it, I grabbed some pics of where I think it was coming from while I was under there.

lamw001 08-25-2008 09:21 AM

Great write up. Thanks.

JoeFromPA 08-25-2008 10:55 AM

How do you feel about shifting quality?


Inigo Montoya 08-25-2008 03:14 PM

The shifting is good, but I did change to redline at about 30K anyway, so I don't have much to compare too.

This was my 60K change

RustyShackleford 08-25-2008 11:48 PM

How important is it to use this Redline stuff, in two different versions, as
opposed to plain ole' Valvoline dino 75W90 (which, I have it on fairly good
authority, is the factory fill) ?

Inigo Montoya 08-26-2008 06:36 AM

You can do that, but looking at other threads on the forum there is an additive in the NS that is supposed to be designed for the manual transmission. I know that for the past 30K things have been great in my car, so I just went with what I knew. I contemplated royal purple, but did not do enough research before I needed to get the change done.

subie_dude05 08-26-2008 06:48 AM

great write up....good job. :cool:

JoeFromPA 08-26-2008 09:20 AM

I believe the NS version (No-Slip) is designed for NON-LSD manual transmissions (i.e. those in the LGT) where the regular 75w90 is the fluid to use with an LSD (Our rear diff in the LGT).


scooby600 08-26-2008 09:30 AM

Very nice writeup, too bad I've already done mine for 30k mile service. btw I got my torx t70 at autozone.

All times are GMT -6. The time now is 06:21 AM.

vBulletin Optimisation provided by vB Optimise v2.6.3 (Lite) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.