Changing Transmission Fluid and Rear Diff Fluid- Notes

This past weekend I changed out Both the Tranny Fluid and the Rear Diff Fluid on My 06 5MT, just a couple of things to note about the change.



1. You do need the T70 Torx bit for the front, but just use a 1/2' ratchet for the rear, I used a couple of extensions for the top bolt since the exhaust gets in the way.

2. Filling the tranny, this took me a bit to find, I removed the engine cover, and the dipstick is on the turbo side, I removed this then used a funnel with a short length of tubing to refill the tranny. Glad I had this around, because you could not get a bottle down there and pour, too cramped and the turbo blocks your sight.

3. For the rear end, get one of the little pumps they sell at any auto parts store, I used Redline, so it doesn't fit into the bottle, but there is no good way to pour fluid into the rear end, either have one of these or get a longer piece of tubing for your funnel.


Summary:
Tools I used-
T70 Torx
1/2" ratchet
2 extensions for said ratchet equaling about 10" long
Funnel with about 2 ft of tubing for fill purposes
Pump from auto store for filling rear end
Phillips head screwdriver for removing engine cover
Ramps and jackstands so my fat a$$ could get under the car

I use Mobil 1 in the raer diff because the bottle is shaped for easy filling...and Mobil 1 isn't so bad a fluid either.

i used a funnel with a long ass tube for the rear end.



btw - how many metal filings were on your drain plug magnet?... Mine had a little more stuck to it than I was expecting.

I switched over to redline - and so far I haven't noticed a huge difference. It did help out in the wifes Mazda6 though.

I noticed a few filings on my drain plug when I changed out my fluids at 60k. Dunno if it's anything to worry about though. I was using 75W90 Valvoline dino in the tranny and rear diff, I put in 80W90 Valvoline durablend this time, since it was on sale. When warm, shifting seems slightly smoother with a little less gear whine; but when cold, it's tougher to get the tranny into first gear. Luckily it rarely gets below 30F where I live.

I used redline for both of the fluids, gear oil for the rear (very different color, and 75W90NS for the front. I did have some metal on the magnets, but nothing I was overly concerned with, most were like fine grit. Hard to tell if it improved my shifting since I just did a short shifter last wed, that made the biggest difference.

I just did this myself today as part of my 30K. I used Red Line 75W90NS in the 5MT and 75W90 in the rear diff.

What in the world did those gorillas use to tighten those rear diff plugs?!? Unbelievable how hard those were on (significantly more than lug nuts), which is pretty silly given they are not load bearing in any way.

Given what many others were finding on their plug magnets, I was rather surprised to find only very fine metallic sludge, no significant chunks of any kind. This is my first gear oil change at 30,003 miles.

On my test drive afterwards, I was glad my shifting is no worse than stock and probably a touch better. Actually, my car has always shifted very smoothly for me, and I do rev match 95% of my shifts, but I was a little worried about non-stock gear oil even though I've used Red Line in the past in other cars. I believe my 2nd gear whine was significantly reduced with the Red Line vs. stock. This gear oil should do quite a bit better in the New England winter compared to the stock non-synth.

I also replaced my air filter and flushed my brake fluid (from ATE SuperBlue to Typ 200 which is yellow but otherwise the same--you can see when you start bleeding the new fluid) to complete my 30K. I had the dealer flush the coolant with a $40 coupon from my local dealer a couple days ago. (I'm in the middle of an oil change interval, so that will come later.)

--Lee

the rear diff plug was EXTREMELY hard to get off on my car as well -- I actually had to use the hydrolic jack in combination with the breaker bar to free the rear plug.--- I think they used some type of locktite or liquid sealant on it.

you didn't use the liquid gasket sealant on the bolt?

Originally Posted by lhsa

you didn't use the liquid gasket sealant on the bolt?

nope - didnt have any on me when i did the swap. The bolt was still so gunked up with the crap they put on it from the factory though, I dont think I'll have any problems.

You know, I used 75W90NS for both the front and rear.

Originally Posted by Legacy05

You know, I used 75W90NS for both the front and rear.

I think that should be fine.

Well ... I would say it has been, car has been driving great heh.

4 in the front, 1 for the rear.

Just took my 05 in for a dash rattle TSB and had them change the front/rear and MT fluid and they only charged me $131.00 to do everything, not a bad price for the mess and not having a lift at home. Gold Rush Subaru in Auburn,CA
Great service/prices
K

Now the front diff is the exsactly the same fluid as the transmission on a MY05 AT, correct?