Subaru Tranny Lube (again...)

Status
Not open for further replies.
M

Michael SR

Joined
Aug 28, 2002
Messages
308
Location
Houston, TX
i read all the posts, there doesn't seem to be a consensus. i'm considering torco rtf in my new impreza, has anyone used it successfully in an application that calls for a GL-5?

it would be good to know if the subaru tranny truly requires a GL-5, or if a GL-4 would work. what would the difference be between the diff in the subaru versus a vw, for instance? is it because of the center diff? (i'm assuming the center diff is lubed with the tranny and front diff.)

neo has a 75w90HD which they specifically state is for GL-4 tranny use, and sexy to synchros, but also meeting GL-5 specs. however, reports on the subaru forum have been both good and bad.

lastly, what is it about petroleum vs synth that has synth GL-5 lubes causing bad synchro action, but petroleum lubes working fine?

thanks.

-michael
 
something else i forgot:

redline australia has a blurb saying they are specifically overriding the subaru oem spec and recommending shockproof in order to solve shifting problems. redline usa says not to use shockproof in a street application, and to use 75w90NS instead.

do you think the redline USA recommendation is inhibited by liability, and that redline australia might be onto something?

thanks.

-michael
 
I have been trying to find answers to these questions for about 5 years.

Yes, petroleum gear oils seem to work best in Subaru gearboxes, unless it's so cold that it's difficult to shift. In low temperatures, synthetic gear oils will make a difference. In my personal experience, the difference is not that great. I have tried two synthetic gear oils and both were still noticeably viscous in very low temps, to the point of increased gear shift resistance.

The factory fill was probably best. I had zero problems. I changed to Mobil 1 75W-90 and at first it seemed to be better, with smoother shifts. In a little while it became much worse, though. I was grinding going into first gear pretty much all the time, especially when shifting quickly. Then I switched to Kendall Elite full synthetic. I still have it in the 2.5RS. I love it. The shifting is very smooth and it completely stopped the first gear problem. It does get think in winter, though. On very cold mornings I can feel increased resistance to shifting.

GL-4 is a big no-no. Subaru requires GL-5.

Center diff is a sealed unit. It does not use gearbox oil.
 
You'll never find a consensus when it comes to Subaru's and gear oil.
smile.gif
I wouldn't use a GL4 either.

I was using Amsoil AGR in my FXT for about 6 months, and just had tranny work done. The 1st, 3rd and 4th gears and synchros were all just replaced under warranty. I don't know if it was because the oil was a little low, or I had some out of spec gears from the factory.

Anyway, I used the Amsoil in my 97 Outback Sport for 3 years without any issues. I had a WRX for a year and used Motul Gear 300 in that. The shifting action didn't feel as quick with that though in the winter.

After I run this dealer stuff (reportedly Valvoline dino) a little longer, I'm thinking of trying Motul Gear 300, Motul Motylgear blend or the Amsoil again.

Cobb Tuning has an old write-up of gear oils. At the time they said the GL4 Redline MTL worked well. Now that they sell Redline, they only carry the GL5 75W90NS for Subes.

-Dennis
 
thanks, i appreciate all the input.

if i try anything, i'll definitely report back.

on the motul, why do people seem to choose the gear 300 when there's another motul that is dual GL-4/5 rated? just an assumption, but wouldn't dual-rated lube have more chance of working properly with the synchros?

-michael
 
Could try Royal Purple Max Gear. It is GL-4/GL-5. John Browning used it in his Toyota Camry tranny with good success. I tried to find the thread but it eludes me. Here is a thread that talks about it some:
Royal Purple Thread
 
I've talked to Tim Slako from Redline Ausrtalia, and they are using Shockproof in a lot of problem road applications, not just WRX's.

The GL4 rating really doesn't relate to synchro performance, it just means that a GL5 that is also GL4 will be safe with the bronze used in the synchros, that were typically attacked by the sulphur EP additives used to attain a GL5 spec. Things like the NEO HD either don't use Sulphur, or it's in a form that is relatively inert.

I think it's going to be one of those things to try something and see how it goes.
The NEO 75w-90HD is a very good lube, and it solved a synchro problem in a mates gf's Peugeot 405Mi6 about ten years ago.
There are good reports on WRX forums here using it.
 
Regarding GL-5 bronze synchros / yellow metal compatibility, I recently received a reply from Swepco when asking about their Swepco 201 gear oil's yellow metal compatibility / corrosion problem etc:

quote:
I want to personally thank you for your interest in SWEPCO Lubricants. We are pleased you are considering SWEPCO Lubricants to help reduce your maintenance and lubrication costs.

SWEPCO 201 Multi-Purpose Gear Lube is perfectly safe to use in manual transmissions calling for EP Gear Lubricants. SWEPCO 201 exceeds API’s latest and most stringent service classification, MT-1. Lubricants meeting the requirements of API MT-1 are defined as a gear
lubricant which has the thermal stability, high temperature cyclic durability and yellow
metal compatibility levels that are not required by API GL-1 through GL-5. Other
characteristics, such as anti-wear, anti-foam, anti-oxidation and compatibility with seal
materials are equivalent to GL-5.

Quality Service is also one of SWEPCO’s trademarks as we give conscientious individual
attention to each of our valued customers. Should you ever have any questions or comments
regarding SWEPCO Lubricants, please don’t hesitate to contact me personally at
(800) 359-5823, fax (800) 736-5823 or email [email protected].

Sincerely Yours,
XXX XXX
Technical Product Manager
SWEPCO Lubricants
Click to expand...
So according to him, when a GL-5 gear oil is MT-1 rated, it will be safe for yellow metals. In fact, I read about this information a while ago in a Subaru forum (NASIOC). And this is confirmed yet again by the technical product manager of Swepco. I am now pretty sure Swepco 201 will be the gear oil I switch to when I reach 15000 miles (well I still have 5000 miles to change my mind...
wink.gif
) BTW, Porsche guys love this gear oil.

[ September 16, 2004, 03:01 AM: Message edited by: SilverGGA ]
 
In TX the RP should be great and Torco also but they're at different ends of the 75w90 weight scale. The RP being the heavier. Nothing else has the load ratings of RP for a tranny, so I would try that first and switch to Torco if you feel something thinner would shift better. Up north the RP can be a little thick in the winter in some vehicles until warmed up. Nothings universal but RP is about as close as you get. Anybody have an idea about way to lower the 75 viscosity of gearmax for winter. I would think 20-33% of RP Synchromax should work as it probably has the same adds as Max-Gear and would drop the viscosity to about where Torco RTF is now. We've gat an RP sponsor here. Any info.

[ September 16, 2004, 09:27 AM: Message edited by: goodvibes ]
 
quote:
Originally posted by Michael SR:
on the motul, why do people seem to choose the gear 300 when there's another motul that is dual GL-4/5 rated? just an assumption, but wouldn't dual-rated lube have more chance of working properly with the synchros?
Click to expand...
Looking at motul.com, I think you might be referring to the Motylgear that I mentioned above. I think more nasioc folks use the Gear 300 because it is 100% synthetic as opposed to a synthetic blend like the Motylgear.

A blend might be a good choice for those that want some friction for the synchros, but easier shifting in the cold. I've never tried a blend though.

Regarding MT-1 spec, Amsoil is also an MT-1 spec. As is Valvoline synthetic, synth blend and conventional.

There's a guy here (David?) that has used Neo with good results. He's "drees" on nasioc.

-Dennis
 
Hello everyone,
My first post on this forum (been lurking for a year or two).

I have a 2004 Impreza RS and I was also thinking of using Swepco gear oil in my tranny. There are also people mixing Pennzoil Synchromesh fluid along with the regular GL-5 75W-90 oil, but I worry about the hypoid gear that is used to drive the front differential.

I just want to know if the 80W90 rating (only rating offered by Swepco)will cause slow shifting during cold weather.

Thanks!

Jay
 
Michael,

I found that the RP Max Gear 75W-90 worked very well in my WRX. In fact, it worked better than the special Subaru synthetic that they now supply for the WRX.

The RP provided good cold weather shifting, much better than the stock dino oil that came in the car.

Ed
 
Hello, I have friends that use the Amsoil series 2000 or something like that in their 5 speed Impreza's with good luck. If you want a good look at Subaru gear oil info please go to Cobb Tuning's website and look at their tech articles. Good info on Subaru specific Q & A's. Brian
 
i think my worry is that a search of any of the suggestions will turn up someone who said it shifted worse than the stock fluid in their car.

but maybe this is the case for any lube, in any brand car, and just the nature of people.

i realized i can't do the shockproof. it's very obviously a unique looking oil, and would probably void my warranty if something happened to the tranny and they opened it up for a look. it's not even GL-rated, right?

regarding the MT-1 spec, i can't find a GL-5 lube that doesn't meet that spec. since i know for sure there are GL-5 lubes that tend to kill synchro action, it doesn't instill much faith that the MT-1 rating necessarily means good synchro action. i guess attacking yellow metals and allowing them to synchronize properly are just two different issues.

(also, i'm pretty sure the MT-1 spec has to do with trucks which don't even have synchros in their gearboxes!)

i think i'm tending towards torco rtf, it appears to be an MT90 clone (at least in application targeting) except with a GL-5 rating.

swepco: is it even available in small quantities?

royal purple: i had a firsthand account of their "testing," and have since been biased against them.

redline 75W90NS: tempting, and under consideration, this was dave's (redline) recommendation as well.

i guess i should ask, does anyone verify the ratings? or can oil companies freely market a lube any way they want on the trust that they have verified it meets the spec?

thanks again for the great discussion.

-michael
 
well, after all that, i decided to try swepco 201. i found it for $40/gallon from some porsche performance place, just ordered it.

i'll post some observations after it's in.

thanks.

-michael
 
Status
Not open for further replies.

Similar threads

T
  • Locked
70W-80 GL-5 MTF for Subarus
Replies
12
Views
921
MolaKule
A
Mazda Hypoid SG1 Alternative
Replies
8
Views
7K
danbfree
ThatNavyGuy
2021 MX-5 Miata 6MT Gear Lube
2
Replies
22
Views
767
dfarr67
dezlpwr
Redline Oil Gurus: Subaru gear oil question
2
Replies
21
Views
7K
SubieRubyRoo
R
BMW Dealership using BG Products for Driveline & Brakes
5 6 7
Replies
124
Views
11K
JustN89
Back
Top