Questions related to Petosin MTF-2 Transmission Fluid

[bluesubie]

I agree not to be worried about running thin MTL in most driving conditions. The much loved Subaru Extra-S used for the front trans/diff in Subaru's requiring GL-5 fluid is ~13.85 cSt's at 100C so it's barely a 90 grade when hot (90 starts at 13.5).

Speaking of Molakule, to this day his Specialty Formulations remains my favorite GL-5 gear lube in a Subaru requiring a GL-5 in the front diff. That's with over 16 years of driving manual Subaru's and experimenting with different gear oils. Too bad he no longer makes it. FWIW, he highly recommends Motul Gear 300 for the rear diff in a Subaru.

-Dennis

[Dezoris]

Originally Posted by SubieNate

I got the word from the man Molakule himself. Pentosin MTF2 should be fine in our transmissions:

http://www.bobistheoilguy.com/forums...on#Post3364612

It's on my list of things to try (mine really isn't that bad to begin with, I have a garage, and it's currently going into summer in the desert), but for now I want to stick with the factory specced viscosity. I've got about 10k to go before my drivetrain transfers over to the extended warranty and I want to keep things in spec for at least the duration of the standard 60k powertrain, just in case.

I'm personally going to try the Motorcraft fluid all the Miata guys love. Similar cost, specifically formulated to deal with problem syncros (Ford had a shitstorm of them with the Getrags in the foci), the miata transmission is similar to ours (Aisin), same viscosity as our factory fill and GL4 rated. It's specs put it in the quality realm of Motul 300 (similar VI and flash point). MS3 and other FWD guys like it as well and many of those cars are known to have crap syncros that are even worse than ours. It's made by Fuchs in Germany so you know the quality is up there.

According to a lot of reading I've done, in moderate temperatures shift performance is less driven by viscosity and more by the friction characteristics of the fluid. Good MTF has friction modifiers that as the synchro cones/teeth/whatever this tranny has get close, the friction r'll report back with my findings. More options are always good and word on the forums for many, many other cars is excellent for the Motorcraft
https://www.fcsdchemicalsandlubrican...on%20Fluid.pdf

Cheers
Nathan

I read what he said about Pentosin and if it feels loosey goosey or makes noise go up 5 cst.

The only time I experience this with this oil is after a track day (same day). Pull off track pack up and drive back home or hotel trans feels sloppy. But once temps drop after cooling off over night feels nornal again. It never feels like that with street driving.

Again this becomes the reality of cars. There is no magic bullet.

[qqzj]

This makes me nervous. Every oil has received some complaints. Really do not know which one is the best to go. Maybe stay with stock MTF. BTW, what is the stock MTF? Nobody seems to care? Today I saw some Royal Purple MTF in local store, GL5 and GL4, just like Motul and with the correct weight. Has anybody tried that?

Originally Posted by OICU812

Yup probably had same experience as me then. As it's been discussed works good for some but not for all due to likely tolerances. The MTF2 feels great in mine, give it a go.

[Cheeseballs]

Originally Posted by Funktional

FWIW........I just replaced with Motul and so far, I hate it. Huge degredation from the stock fluid.

Same here. Shifting from 1-2 is so clunky and almost grindy, I feel like I'm damaging something (yes I know how to shift properly). This occurs on perfect 75° F. days as well as colder temps, but at least it goes away after driving for a few minutes. This never occured when I had the factory fill.

Total waste of money for me. I don't know if I should try Pentosin or just go back to the factory stuff.

[Funktional]

Originally Posted by Cheeseballs

Same here. Shifting from 1-2 is so clunky and almost grindy, I feel like I'm damaging something (yes I know how to shift properly). This occurs on perfect 75° F. days as well as colder temps, but at least it goes away after driving for a few minutes. This never occured when I had the factory fill.

Total waste of money for me. I don't know if I should try Pentosin or just go back to the factory stuff.

I haven't quite figured out what I'm going to do. There's a chance I may deploy in October so I may end up selling the FR-S, if I don't I'll probably give the Pentosin a go or maybe just go back to factory fluids.

[imom]

I had MTL and just replaced it MTF2 +... the MTL was completely clean and didn't have anything stuck to the drain plug...but it was only 2K miles when I replaced stock with MTL. MTL works okay when the weather was warm, but still still sucked when cold. Motul I suspect is too thick for the specific temp 40C.

I'm 90% happy with Pentosin for daily driving. I would recommend doing the swap and it's not expensive for the aggravation of shifting. I don't know if the tranny mounts or the shifter springs helped as much as Pentosin...but I would do that first. I would not do factory fluids...it sucked so why go back to it? I hope that helps.

[OICU812]

The miller nano oils look interesting indeed. They have our weight and specifications to.

[504]

Originally Posted by SubieNate

I'm personally not comfortable with running a fluid that has roughly half of the viscosity of the specced fluid at 100C.

Has anyone looked into average transmission fluid temps during hard driving at moderate to high ambient temperatures?

I'm personally trying the motul first, but I'm on my way to a long hot summer here in the desert.

I am very curious about the Ford motor craft "honey" that the miata guys rave about for the nb and nc six speeds. It's specs from Ford make it look like great stuff, but I've found a lot of conflicting info on its actual properties on bitog. Some say it's made by Fuchs, some say castrol, the ford data sheet I found says viscosity of ~15 at 100C but other sources say it's more like 10 ( including molauke) and basically a diesel motor oil.

By the bottle specs, it seems perfect. High VI, thin at lore temps, gl4, specifically for transmissions, and 75w-90 spec for warranty. But that doesn't line up with what molauke or big Jim say about it on the forums over there.

Cheers
Nathan

Actually OEM manual transmission fluid is under 10Cst at 100 degrees C even though the car specifies 75w-90

http://www.ft86club.com/forums/showthread.php?p=1644314

[Proof]

I noticed now that it is warmer out my Gearbox is loud as can be when off load. I am also running the Motul. I have a boat load of the Pentosin in the shop so I think I will give it a go.

[dwb]

Thank you all for supports and sharing your experience and so on.
Finally, I got transmission and rear differential fluid changed today.
I really love it. It shifts like butter! no more clunky, no more grinding noise.
I shouldve done it earlier.. I regret so much
Even though weather gets warmer, there is no problem shifting at all.
Those of you having problem shifting 1st to 2nd gear, I strongly suggest you to change transmission and rear differential! Especially, for people who live in north area, get PETOSIN-MTF2!!

Thank you all again,

[Rocket.BRZ]

so whats the story with this gear oil on the track? is it safe?

[Dezoris]

Originally Posted by Rocket.BRZ

so whats the story with this gear oil on the track? is it safe?

Myself and @kiichiro have run it at the track. He has a lot more miles and power on his and extreme heat.

After track usage when trans is very hot the gear action will feel more loose as a sign the oil has thinned out. But returns to normal when cooled off. I sent a UOA of the oil after a 2+ hour track session and 13k miles and the oil was good except for aluminum.

I have a second 7k miles (Including track time) sample being sent for testing this week and will post the results. I have to admit sometimes the trans feels loose but I have never had one grind, or any notchiness since it has been installed.

[Rocket.BRZ]

Originally Posted by Dezoris

Myself and @kiichiro have run it at the track. He has a lot more miles and power on his and extreme heat.

After track usage when trans is very hot the gear action will feel more loose as a sign the oil has thinned out. But returns to normal when cooled off. I sent a UOA of the oil after a 2+ hour track session and 13k miles and the oil was good except for aluminum.

I have a second 7k miles (Including track time) sample being sent for testing this week and will post the results. I have to admit sometimes the trans feels loose but I have never had one grind, or any notchiness since it has been installed.

Sounds like redline is the better choice?

[Dezoris]

Originally Posted by Rocket.BRZ

Sounds like redline is the better choice?

I don't think I can say at this point. What I know is its the best fluid so far for shift action and smoothness during normal operation. High high heat? So far no issues with UOA or mechanical issues yet. But without long term use and data just dont know.

My gut tells me its the best street fluid. If you track more than 3-4x a year probably use something thicker, but expect more notchiness.