[Turninconcepts.com]

As some of you may know I've had a really nasty 4th gear grind for a long time. Thinking that the synchro was shot I picked up a spare 6MT about 4 months ago. Sadly, I have not had time to put it in my car.

In anticipation of the tranny swap I began to ponder the best fluid to run. Over time I've tried all sorts of fluids in my tranny. Some straight out of the bottle, some popular ****tails, and some ****tails of my own twisted thinking. I wasn't really happy with any of them.

So, I started researching. Researching, reading, thinking, reading some more, and continuing to research.

Bottom line there are two big name company fluids out there that really seem to have a good history with the Subaru trannies.

Those two fluids are Motul Gear 300 and Mobil's Mobilube SHC (please note this is NOT the Mobil tranny fluid you can pick up at autozone). There's also a third option that's a small batch, custom mix stuff, but I choose to look more at that big names at this time.

In my research I found that the SHC had been discontinued, and replaced with a Mobil Delvac. I wasn't really interested in trying a new fluid as I was looking for proven, time tested results.

This left the Motul Gear 300. It's also the most convenient for me to get as we have an account with Motul.

Anyway, I ordered up a case of Motul Gear300. Now, this comes in two flavors, 75-90 and 75-140. I choose the 75-90.

Now, this still didn't mean that I had a lot of time to swap that tranny, and it got me to thinking.

Here was my thought process - if the synchro is shot there may very well be some yellow metal sitting in the bottom of that pan. I've never pulled the pan to check, and it would take less time to check that than swap the tranny.

So, I drained the latest ****tail, and completely flushed the tranny. For the flush I filled the tranny with Acetone, ran it for a few minutes with the car in the air, shifted through all the gears a number of times, and ran it for a few minutes more, and then redrained.

Now, I know folks are going to scream - "but the Acetone will decay your seals!!" "Oh, bad move Clint." or just "Clint, you're an idiot." <- this one is nothing new.

First off, I am not recommending you do this at all. I did it because I wanted a completely clean slate to start from, with no contamination. Second, it was only in for a total of less than 15 minutes. Third, I have a spare 6MT sitting on a pallet right here. If I majorly screwed something up doing this I would find the time or make the time to swap the trannies.

So anyway, I drained the acetone. Front diff came out clear, but the tranny fluid came out dirty. Another quick rinse, and it came out much cleaner. Enough to make me happy.

I then dropped the pan.

I found lots of fuzz on the magnet. This was to be expected as the tranny has over 70K on it.

In dropping the pan I was very careful not to spill it so I could inspect the contents. I slid out from under the car can began to feel around in the bottom of the pan for any yellow metal bits. I did not find any. This gave me a bit of hope.

I let the tranny air out for a good long time to let the acetone evaporate. In the mean time I took the opportunity to clean the pan of any of the grease, road grime, and RTV left on the flange. (BTW, liquid laundry detergent and water is great for this). I also cleaned up the RTV on the tranny case for the flange.

After a good long while I used some fresh RTV to reinstall the pan, replace the plugs and fill the case with the Motul Gear300.

I let the RTV set for a while before driving, and then took it out for a spin. I got a 4th gear grind two miles in, but I was driving gently to make sure the fluid had enough time to work into all the nooks and crannies, and get up to temp. Once it got to temp no more grind.

I've now had the Motul in for 300ish miles. In that time I have been BEATING on the tranny to try and get it to grind. Seriously, beating on it. Generally just being and asshat in my shifts (hey, I've got a spare sitting on a pallet).

So far, I have no more 4th gear grind, and no new grinds.

So far, I am very happy with this fluid.

Now, I know our trannies are rather sensitive to the fluid that goes in them, but never would I have thought they were this sensitive. So far it looks like they are.

I know I don't have a lot of miles on it yet, but I will keep driving it to see what happens. I will update here as I hit major milage milestones to let folks know how it's running.

Next on the list we'll be trying it on the new TiC RSX Type S to see if it smoothes out the 6MT on that one as it feels very un-Hondalike on the tranny.

[fullerton]

interesting results.

no junk in the tranny at all (except for fine shavings)?

mine is happy so far, but it does like to reach operating temp before 5th gear is used. but- a new oil that fixes things is nice.

[jph]

nice review!

if you don't mind, here are my $0.02

after i switched to motul gear 300, it definately felt smoother.

i didn't have any grinds before though, neither do i have them after switching.

but one thing that i noticed is the fist 5 minutes of driving in the morning, when everything is still cold. it was now just as smooth. no more fighting the shifter into place at the first turn or stoplight, if just plops right in.

taking a slow tight turn ? downshifting to 1st is no longer a problem!

i like the motul gear 300 for those reasons.


J.

[wdb]

I'm due for a transmission oil change and was getting ready to do the same thing; research, research, research. Clint, what do I owe you for saving me all that time?

[Turninconcepts.com]

Originally Posted by wdb

I'm due for a transmission oil change and was getting ready to do the same thing; research, research, research. Clint, what do I owe you for saving me all that time?

You can buy me a beer if we ever meet up outside of the board.




mmmmmmmm...... beer.

[Mykl]

.........or you can just run Subaru Extra-S and *KNOW* that it's going to work.

[Turninconcepts.com]

Originally Posted by Mykl

.........or you can just run Subaru Extra-S and *KNOW* that it's going to work.

Yes, you certainly could. The problem is finding stocking dealers. Not all of them stock it or even know of it.

In fact, write up a review on it, and we'll start of list of what DOES work with milestone updates. This seems to be some knowledge that is hard to find in one place, and we could finally fix that and help others in the future.

[LOLSTi]

Originally Posted by Turninconcepts.com

In fact, write up a review on it, and we'll start of list of what DOES work with milestone updates. This seems to be some knowledge that is hard to find in one place, and we could finally fix that and help others in the future.

Great idea.
p.s. ****tail.

[Mykl]

Originally Posted by Turninconcepts.com

Yes, you certainly could. The problem is finding stocking dealers. Not all of them stock it or even know of it.

In fact, write up a review on it, and we'll start of list of what DOES work with milestone updates. This seems to be some knowledge that is hard to find in one place, and we could finally fix that and help others in the future.

Some dealerships will sell it by the quart, just have to call around. I know that Subaru of Gwinnett will sell it by the quart. But I'm going to go ahead and buy the big bucket from www.subarugenuineparts.com

[Rac10000]

Great info Clint! Changing my tranny fluid is on my to-do list before this years track season. I have not decided which brand to use but I'm thinking I might give the Motul a try based on your experience and some research I have done. I am also a huge fan of Amsoil and many people have had great results with their SEVERE GEAR 75W-90 (SVG). I just need to look into it a little more.

Can we order the Motul though you?

[LOLSTi]

Originally Posted by Rac10000

Can we order the Motul though you?

I lied. Motul died.

I know Clint has some.

[Turninconcepts.com]

Originally Posted by Rac10000

Can we order the Motul though you?

Not yet. I have a bunch sitting here, but I'd like to get more miles on it, and see what I think before I start selling it to others based upon my personal results.

[Rac10000]

Originally Posted by Turninconcepts.com

Not yet. I have a bunch sitting here, but I'd like to get more miles on it, and see what I think before I start selling it to others based upon my personal results.

Okay. That sounds like a good idea to me. I am not going to buy anything for a few months anyway. Just let me know if you decide to sell it.

[AnorexicSTI]

Originally Posted by Turninconcepts.com

Yes, you certainly could. The problem is finding stocking dealers. Not all of them stock it or even know of it.

In fact, write up a review on it, and we'll start of list of what DOES work with milestone updates. This seems to be some knowledge that is hard to find in one place, and we could finally fix that and help others in the future.

FWIW, I talked to my local raceshop and they have Motul Gear 300 as well... but felt it was more geared for European cars... he said for Subarus, a local track guy is using Redline 75W90 gear oil for his STI... I'm torn now too... Redline or the Motul...

[wdb]

Originally Posted by jph

after i switched to motul gear 300, it definately felt smoother.

i didn't have any grinds before though, neither do i have them after switching.

but one thing that i noticed is the fist 5 minutes of driving in the morning, when everything is still cold. it was now just as smooth. no more fighting the shifter into place at the first turn or stoplight, if just plops right in.

taking a slow tight turn ? downshifting to 1st is no longer a problem!

i like the motul gear 300 for those reasons.

Those sound like my symptoms; no grinds, but tough shifting when cold + occasional balkiness into 1st. Can you tell us how long you have been using Motul Gear 300? Time and mileage would both be useful.