MOTUL 75W-90 GEAR 300 Synthetic Gear and Differential Fluid

[Soda Popinski]

It's time for me to drain and change my front + rear diff and while I'm at it, I was going to completely flush my 5EAT back to the torque converter.

 

I found by searching that 75w90 Synthetic works fine for ours... The dealership near me said that they use synthetic for the STi's diffs. Legacy models get the cheap generic stuff.

 

Motul makes this product:

 

MOTUL 75W-90 GEAR 300 Synthetic Gear and Differential Fluid

 

Here's the blub from the site selling it:

 

This MOTUL SAE 75W90 gearbox and differential fluid is a 100% synthetic ester based oil, which can be used in tranmissions and rear differentials under all conditions of use -- street, track and racing. This oil has proved its qualities and resistance to extreme conditions. Turner Motorsport uses MOTUL fluids in our own championship winning BMW race cars, as well as our own personal street-drive vehciles. We would not hesitate to use this MOTUL 75W-90 GEAR 300 gear oil on our own personal vehicles, and neither should you. Be sure to check your owners manual before selecting oil products for street applications. This is a 1 liter bottle, so be sure to order enough for your specific application. API GL-5. MIL-L-2105D.

 

Dimensions: 3 X 4 X 13

Weight: 1.60

 

Regular Price: $19.99 (USD)

-On Sale For: $17.95 (USD)

 

I called the dealership and they indicated that I would need a Torx T-70 bit for the front, and a regular hex socket for the rear diff. I would also need a crush washer for the front diff T-70 plug, and liquid gasket on the threads of the rear plug.

 

So my questions:

 

a) Does the product linked above work with the 2008 Legacy GT w/ 5EAT for the AT, front and rear diff? and if yes:

 

b) How many liters should I order?

- Dealership said rear diff uses just under 2 pints...

- Dealership said front diff uses just about 2.5 pints...

- Searching threads around here I read that the 5EAT uses about 10-11 quarts.

 

Would 14 quarts of the above linked product be enough and have some left over as well?

[BAC5.2]

You can't use gear oil in place of ATF.

 

The fluid you linked will work for the front diff and rear diff. But you need Dextron3 for the transmission.

 

The rear diff uses one liter, the front diff probably uses another liter, but your owners manual will tell you.

[Soda Popinski]

You can't use gear oil in place of ATF.

 

The fluid you linked will work for the front diff and rear diff. But you need Dextron3 for the transmission.

 

The rear diff uses one liter, the front diff probably uses another liter, but your owners manual will tell you.

 

 

So this product would work for the 5EAT?:

 

MOTUL Multi ATF Automatic Transmission Fluid / Gearbox Oil - 1 Liter bottle

 

Blurb:

 

MOTUL Multi ATF (automatic transmission fluid) and gearbox oil. ATF is commonly used in many BMW manual gearboxes and power steering systems (be sure to check your owners manual to be sure). This is a 1 Liter bottle of MOTUL ATF, which is formulate using MOTUL's Technosynthese® technology. Compatible with GM Dexron III / Ford Mercon / Allison C-4 / Caterpillar To-2 Voith / ZF. Turner Motorsport uses MOTUL lubricants gear oils in our own championship BMW race cars, as well as our personal BMWs. We believe MOTUL to be the leader in oil and lubricant technology, for both street and track applications. This is a 1 liter bottle, sold individually -- please be sure to purchase enough for your application.

 

Dimensions: 4 X 5 X 14

Weight: 1.60

 

Regular Price: $13.99 (USD)

On Sale For: $12.49 (USD)

[BAC5.2]

That should work for the transmission. The Gear300 you posted in the OP will work for the front and rear differentials.

 

I have no idea what the general recommendation is for ATF though.

 

A drain-and-fill of ATF is only 5 quarts, or so I believe. A full flush requires 12 quarts, but you can't do that without a flush machine.

[fishbone]

There are 3 places you will drain and you will use 2 different fluids:

1 fluid for the front and rear differential, 1 for the automatic transmission.

You need to make sure that Motul fluid meets the Subaru spec, ATF-HP. If not, you are gambling. Why not look at a local, tried and proven synthetic ATF that you will also be able to get for cheaper, such as BG, Valvoline or Amsoil?

 

LE: I do not see Subaru, ATF-HP or Idemitsu mentioned anywhere on the Motul stuff. I would go with something else.