I have been told by my local 86 group and my STI friends to always go with Motul Gear 300. I want no part in a subjective debate, but just curious if I am missing something? Is Motul too expensive? Not good for our cars? I am about to change my fluids again after doing Motul in both Tranny and Diff about 30k miles ago and am open to suggestions if there is a different consensus on what is best for our cars.

Short answer, yes.

Long answer:
On reflection I do think my transmission could be described as crunchy entering every gear, particularly when cold. At the time, I just considered it normal, but I could see how someone could find it annoying. In my experience, amsoil fixed that. It's now smooth with an occasional crunchy shift when "cold", but that's just the nature of the transmission. I use quotes because I haven't driven it in under 70 F temperatures yet. Any winter driving may have a different set of issues.

Just to be clear, your transmission is not making grinding sounds right? I'm defining crunchy as it feels like you are crushing a bag of potato chips when entering a gear.

Your results may be a bit different of course, but it sounds like the amsoil MT oil will at least be a step in the right direction.

I was considering both motul and amsoil but it looks like overall preference on BITOG was amsoil. If you want to experiment, I say go for it. My motivation was just to see what would happen, and am happy with the results of the transmission oil change. Still need to try some of the friction modifier in the diff. IMO, the diff needs some friction modifier in the oil, and the amsoil doesn't come pre mixed.

Hi Spuds,

Thanks for your detailed answer. Appreciated it.

To answer your question, No I don't have any "grindings" in my transmission. It just feels crunchy going into gears. What I can describe is that I can feel I am moving a gear lever through something that is moving inside. Feels like dragging my stick through the gravels or something. It is not very obvious but it is kind of annoying. Moving the gear lever through the gate is quite sticky and heavy when the transmission is cold. It just make driving the car tiring and worrisome.

When cold (my cold means when I first drive the car after let it sit overnight as I live in hot climate morning temp is around 85 degree F) the problem will be worse as sometimes I can feel and even "hear" the crunch for the first few shifts but it will get better and better the longer I drive it. It gets best when I drive it really really hard like when I was running in the race track and that was when my transmission felt SWEET!!

How many miles did you have before changing the trans oil? Mine is currently at around 8,000 mile and still on factory fill.

Dragging a stick through gravel is actually a really good description. :thumbsup:

About 35,000 miles on factory fill before I changed it out.

The Motul is popular but the general consensus isn't always the best way to go. If you look enough there are quite a few complaints about Motul in these cars. No doubt it's good, but I believe most people in this thread are kind of experimenting to find what's best. Also, Amsoil is available locally for most people. That said, I would be interested to hear from anyone that has tried both Amsoil and Motul back to back.

Gear 300 is GL5 rated, which while acceptable in the 86's differential, it is not acceptable for the transmission. Other FWD Subaru's do require GL5 in their transaxles due to the incorporation of a differential (hypoid gears) into the unit, but our transmission does not have this.

That's not to say Gear 300 will immediately make your transmission explode. You could probably use olive oil for a while and get away with it. However, the additives which make the oil GL5 rated also have a detrimental long term effect on the yellow metals used in any transmission designed around GL3/4 oils, which includes ours.

Oh Hot Damn!! This just blew my mind with facts. :thanks:

Thank you!

Here's a nice read on the topic:

http://www.rtsauto.com/wp-content/up...nsaxle_oil.pdf

After putting about 1k miles on the car with amsoil in the transmission I will say that the second gear shift loves it. Second gear is almost always smooth at anything but the coolest temperatures. On the other hand, strangely, 5th gear seems to not like it as much. I have to shift to 5th more slowly now or it will grind when it never would before. Though, this could be a result of the transmission mount stiffening insert I installed at the same time. I'm sure the improvement in second gear is due to the amsoil though. In conclusion, I recommend it. I'll probably stick with it long term.

I'll pay attention to the higher gear shifts and report back.

Anecdotal chime in - my experience with Amsoil mirrors the OP. The gearbox shifts easier and smoother with their oil in it.

Drove it today, and 5th feels the same as other gears to me. I know that I had to get used to the shifter bushing when that went in and had to be more precise with the shifter. Agree with above assessment.

Some Amsoil MTG users experienced the same thing.

http://www.ft86club.com/forums/showthread.php?t=71030
http://www.ft86club.com/forums/showthread.php?t=118607

At what speed did you have the 5th gear grind?