6MT Gear Oil

[clemsongt]

I have been trying to decide with what to replace my supposed "lifetime" transmission oil with since I have about 75,000 miles on my car. There are a good many options out there in the form of 75W80 and 75W90 weight oils that people on this forum have been using. Many people have been using these oils in their trannies and have experienced difficulty shifting in the colder months. This leads me to believe they might not be the right oils. My reading has led me to the following threads:

Audizine: 6MT Gear oil questions. (Help Fast:) GL4? GL5? Conflicting information (http://www.audizine.com/forum/showthread.php/345489-6MT-Gear-oil-questions.-(Help-Fast-)-GL4-GL5-Conflicting-information?highlight=gear+oil)
Audizine: Manual transmisson question? (http://www.audizine.com/forum/showthread.php/354958-Manual-transmisson-question?highlight=gear+oil)
Bobistheoilguy: VW lifetime fill (http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=706595&page=1)

After reading the Audizine threads Tusin points out that our transmissions have soft metal components (brass) that requires a GL4 fluid, but at the same time the GL5 fluid is best for transmissions with hypoid gears which our transmissions also have. The conclusion from him is that a gear oil fit for the brass syncros is much more important than for the hypoid gear for longevity.

Tusin and Brillo also state that the OE fluid is a 75W90 weighting, but I have yet to find that anywhere else. Numbers from Tusin:

OEM Viscosity @ 40c is 76.6 @ 100C is 14.2
Redline MT90 @ 40c is 90 @ 100c is 15.6
MTL @ 40c is 56.2 @ 100c is 14.2
Royal Purple 75w90 @ 40c is 132.3 @ 100c is 19.2

I would love to know where these numbers come from, cause as you can see the ones below are a bit different...

Numbers from TDIclub via Bobistheoilguy:


Viscosity Comparison @ 100 C
6.3 = OE G52 fluid
10.6 = Redline MTL 70-80
13.8 = Amsoil MTG 75-90
15.2 = Motul Gear 300 75-90
15.6 = Redline MT-90 75-90
15.0 = Elf Tranself Synthese FE 75-90
16.7 = Motul MOTYLGEAR 75-90

I am trying to decide if there is anything aftermarket that will work for my transmission, or if VAG has done a good enough job concealing what the OE fluid (G052171A2 (http://www.ecstuning.com/Search/G_052_171/ES6601/)) actually is to the point that I have to buy their stuff.

Any *intelligent* conversation is very much welcomed.

[Jay-Bee]

I would like to hear more "technical" talk on this too before I make a decision, i've read a few other threads and it seems like most are on the fence.

I ran Motul Gear 300 in my MK4, I really liked it, but getting close to -25*C it was stiff as hell for the first 5 mins of driving, 2nd gear was always sticky and I would skip it sometimes till it warmed up, thank VAG for their synchro rings. Now that i'm in North Alberta we can see -45*C in the winter, but I won't be taking the B7 out in that too often, thank god for the Ford work truck that I treat like a little 2 cent whore.

But once warm the Motul had great engagement feel, clicked nice and smooth into all gears and felt like a new trans when I switched it @ 180K kms

I've also heard of many people using GM Syncromesh on MK3/MK4s... any details on that? It's a full synth oil, the way it's designed it's not a standard 75w90 weight rating and responds very good in the cold.

I also always ran Motul engine oils in my MK3/MK4

Royal Purple numbers look way too thick even hot. But why are the OEM numbers so low in the second set of details?

[yettavr6]

I'm running Lubro-Moly GL5 in mine. I read enough about the debate on this, and Lubro-Moly swears that it is safe for our transmissions, so i felt comfortable running it. It says right on the bottle that it is perfect for manual transmissions, and pretty much all modern manual transmissions use brass syncros. I know some people would still say I'm crazy, but I spent hours researching and googling, and came to the conclusion that its fine. So far I have not noticed any ill effects, in fact i haven't noticed any difference from the stock fluid. It was very stiff this winter, but it was my first New England winter and when I lived in PA my car was garaged, so that's not really a far comparison.

[mr shickadance]

I switched to motul 300 .... I am a big fan of it

In the tech section there is a DIY by b7kevin that will also help you out

[Jay-Bee]

I switched to motul 300 .... I am a big fan of it

In the tech section there is a DIY by b7kevin that will also help you out

In both trans and diff?

I've seen the DIY, and I did the change myself on my MK4 and still have the 17mm hex socket, was your's the security bit, there seems to be a toss-up for 07/08 models if they have it or not.

[mr shickadance]

security bit? im confused by that can you expain it more?

and yes, in the post i asked him about doing motul 300 in both and he said its 100% fine its just that motul 300 is pricey so he went with a cheaper option in the rear, personally i think the costs equal out because you need 1.5 quarts in the rear, leaving you with .5 left over, but if you use 300 for everything it comes out to 6 quarts total. so i used 300 for everything its been fine for me.

[yettavr6]

I have an '08 and it was a standard 17mm

[Jay-Bee]

Like this: http://www.sears.com/shc/s/p_10153_12605_00929891000P?sid=IDx20070921x00003c&srccode=cii_10043468&cpncode=21-116601793-2

Guess I was wrong, or confusing it with something else.

[mr shickadance]

umm for me it was a 17 mm allen key that did both the fill and the drain.....very simple procedure, and b7kev was not kidding the fill plug is immediatly to the left of the axles

[clemsongt]

I am glad that we now know that the 17mm allen is what works for the drain and fill plugs, but where does one go to get intelligent discussion on what is actually asked? This forum is a great community, but real car discussion is pretty hard to come by.

Any suggestions?

[Scotty@Advanced]

After reading the Audizine threads Tusin points out that our transmissions have soft metal components (brass) that requires a GL4 fluid, but at the same time the GL5 fluid is best for transmissions with hypoid gears which our transmissions also have. The conclusion from him is that a gear oil fit for the brass syncros is much more important than for the hypoid gear for longevity.

Tusin and Brillo also state that the OE fluid is a 75W90 weighting, but I have yet to find that anywhere else. Numbers from Tusin:


I am trying to decide if there is anything aftermarket that will work for my transmission, or if VAG has done a good enough job concealing what the OE fluid (G052171A2 (http://www.ecstuning.com/Search/G_052_171/ES6601/)) actually is to the point that I have to buy their stuff.

Any *intelligent* conversation is very much welcomed.

We stock an OEM equivalent..

http://www.advancedautomotion.com/product_info.php?products_id=139

It's a direct cross to G052171A2, and has worked well for many folks.

The GL rating is rather outdated. GL5 came about when Limited Slip differentials came about in the 60's. LSD's could not use typical GL4 gear oil so sulfur containing compounds was used to modify the lubricant's properties to give lsd's good life and engagement characteristics. However GL5 could not be used in manual transmissions as with heat and time, the sulfur compounds would combine with the copper in brass syncro rings and create copper sulfate (or sulfide I can't remember), slowly eating away the syncro rings. So you could not use GL5 in GL4 applications.

However fast forward to today with modern synthetic additives and slufur free compounds most gear oils will meet GL4 and GL5 ratings, and still be safe for copper based metals. The main specs that must be met now are if the fluid has the proper shear strength (change in viscosity as fluid is put under pressure and heat), viscosity, and lubrication properties. Many of the one size fits all lubricants (redline and royal purple) are actually too slippery for effective syncro operation. Redline also has very poor shear strength.

[mr shickadance]

I am glad that we now know that the 17mm allen is what works for the drain and fill plugs, but where does one go to get intelligent discussion on what is actually asked? This forum is a great community, but real car discussion is pretty hard to come by.

Any suggestions?

Exsqueeze me but you asked if there were anything you could use aftermarket that would work..... We told you the answer to that (you could have searcjed for that info)

In terms of intelligent discussion i dont know what your reallt after, do i know why the oil works? No i dont but im pretty happy with the results i got, imo the motul 300 feels much beyter then the oem stuff, mind you i had not switched my fluid bc it was bad, i still had an easy 50k still to go, i switched bc it seemef like a fun thing to try tosee if i could tell a difference, everything felt smoother, not loose but smoother

[clemsongt]

Exsqueeze me but you asked if there were anything you could use aftermarket that would work..... We told you the answer to that (you could have searcjed for that info)

In terms of intelligent discussion i dont know what your reallt after, do i know why the oil works? No i dont but im pretty happy with the results i got, imo the motul 300 feels much beyter then the oem stuff, mind you i had not switched my fluid bc it was bad, i still had an easy 50k still to go, i switched bc it seemef like a fun thing to try tosee if i could tell a difference, everything felt smoother, not loose but smoother

What Scotty brought to the discussion is what I was after. I was not looking for "I put in xxx and it worx gud." I was looking for talk about weights, compositions, and how things compare in a technical sense to the OEM fluid. If you actually look at my original post and read it, you would see that you can't tell me to search as I've referenced posts from multiple forums on the subject. Yes, I can find many gear oils out there, but what I want to know is which, if any, of them are like the OE fluid.

[clemsongt]

557 posts about transmission lube... (http://forums.tdiclub.com/showthread.php?t=132884&)

There are a few posts on there about the Fuch's. Some people claim that it is actually the OEM supplier, while others question that because there is no documentation to says as much. Fuch's does self proclaim that they meet the VW specs (http://www.opieoils.co.uk/pdfs/FUCHS%20-%20TDS/TITAN%20SINTOFLUID%2075W-80.pdf), but I cannot seem to find the actual VW TL 521 71 spec to say VW thinks it is a good substitute.

I am leaning towards getting the Fuch's because $15 (thanks Scotty) is a good price compared to the $25 for OE stuff.

[Scotty@Advanced]

557 posts about transmission lube... (http://forums.tdiclub.com/showthread.php?t=132884&)

There are a few posts on there about the Fuch's. Some people claim that it is actually the OEM supplier, while others question that because there is no documentation to says as much. Fuch's does self proclaim that they meet the VW specs (http://www.opieoils.co.uk/pdfs/FUCHS%20-%20TDS/TITAN%20SINTOFLUID%2075W-80.pdf), but I cannot seem to find the actual VW TL 521 71 spec to say VW thinks it is a good substitute.

I am leaning towards getting the Fuch's because $15 (thanks Scotty) is a good price compared to the $25 for OE stuff.

I've heard a rumor the Fuchs is an oe supplier as well, but have not seen any actual proof, but it's certainly possible they formulate for the OE.

VW will not say if any other brand (other than their own) meets their specifications, it's bad business to do so.

Most of the time oil companies have to reverse engineering a factory oil to come up with a formulation. What redline and most of the mainstream (royal purple, castrol, mobile 1 etc) will do is formulate an oil or a few different mixes of oils that meet most OEM specs (toyota, MB, BMW, Audi, VW, Seat, blah blah) so they can increase their market for their product while offering a single or very few different products saving costs with production. This fails sometime as trying to meet specs for the mainstream of vehicles, a few key specifications for particular manufacturers is not met meaning substandard performance in those applications.

What Fuchs has done is tailor their product to meet a specific subset set of vehicles, and offer a complete line of oils each being tailored to a specific series of gearboxes, or group of manufacturers. What's great about the VAG conglomerate is that (Seat, VW, Porsche, Audi, Skoda, Bentley, and Lamborghini etc) use similar equipment meaning a similar set of lubrication specifications. A company can cover all those makes of vehicles with a few distinct formulations.

In a nutshell the Fuchs is the right shit at a very competitive price.

[clemsongt]

Thanks Scotty. When I order some stuff, it's definitely coming from you. [up]

[Brillo]

My friends and I have tried a number of different manual tranny oils including Redline MT90, the Mobil 1 product, and Amsoil. We all went back to Pentosin MTF2 which runs about $20 per liter. The main complaint was cold weather shifting - all but Pentosin sucked. The Pentosin oil is a 75W-80 and it looks and smells exactly like the oem oil. It's fully synthetic and made in Germany. Many of the BMW folks with MTs use it and apparently like it. Some claim that it is the OEM fluid or that it is approved by BMW. I have no way to check the veracity of these claims.

[shiro1745]

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[Hugh@EuropaParts]

Good thread guys... Here is a link to the gear oils we have in stock, they include Lubro Moly Synthetic 75W90 Gear Oil, Motul GEAR 300 75W90 Gear Oil, Motul MotylGear 75W90 Gear Oil. CLICK HERE (http://www.europaparts.com/category/fluids.html?subcategory=191)