6MT Gear oil questions. (Help Fast:) GL4? GL5? Conflicting information

[Tusin]

So I am replacing my gear oil in the front diff (6MT Quattro 2.0T). And am coming up with a lot of conflicting information. I am planning on driving 40 miles this afternoon to pick up some Redline MTL/MT90, but now I do not know if that is ideal.

Our cars have a hypoid gear system. According to Redline's website, MT90 and MTL is NOT suggested for hypoid gears. But I have read a few posts of people using it with good results.

Our factory fill is G052-911-A2 which I cannot find to much info on. But according to this post (about half way down the page) http://www.vwaudiforum.co.uk/forum/showthread.php?t=46895&page=2 you see that G52-911 is a GL-5 fluid. So something like Lubro-Moly GL5 (which is compatible with Hypoid gears) would be compatible.

BUT, I have also read that our transmission needs GL4 due to brass syncro's. If anyone can help sort out this all out, I will be in your debt! :)

[nycion]

You mentioned front diff, but I guess you meant manual gearbox. I'm not a big fan of the stellarship, but in this case I would get the oil (fluid) from Audi. It will probably cost you $70 - $100 but it's woth it since you don't really need to replace it that often. BTW, why do you need to raplace it anyways - do you hve at least 100k on it?

[Tusin]

Our gear box, differential and torsen diff all share the same fluid. I am changing it, because I bought the car used and I always change fluids. And the factory fill (if that is what is still in there) is pretty damn hard to shift when it is cold (I live in Alaska so it is cold for LONG periods of time lol).

[chrislane31]

Get new OEM stuff. I replaced mine with the Redline GL5 stuff and it is a little hard to shift until it warms up.

[Tusin]

Is there a reason you went with gl5?

[Hyphy]

Is there a reason you went with gl5?

I'm guessing cause of the cold weather (the thickness of the -oil).

[ECS Tuning-Audi]

Well there is a difference between MTL and MT90. MT90 is 75W90 Gl4 and MTL is 70W80. Livinging in Alaska, I'd think you would favor 70W80 MTL. I'm not sure how much you are paying for it in Alaska locally, but we stock it for 12.60 a quart. That is a pretty good price. If you were waiting to get a few things for your car you might want to put a little cart together and order it up to Alaska. Here is a link to Redline MTL = Click here for Redline MTL (http://www.ecstuning.com/Audi-B7_A4-Quattro-2.0T/Drivetrain/Differential/Fluid/ES1502/?salesrep=CArmbruster&utm_source=audizine&utm_medium=forum&utm_content=CArmbruster&utm_campaign=postreply). We've been using a host of Redline products here and have had great luck with quieting shifts and smoothing them out, etc.

[quickaudi07]

Chris @ ECS is right.

I had a VW Golf VR6 6 speed Mt. I had problems with 3rd gear. It will grin left and right don't metter if it was cold or hot. I got Red Line Oil from ECS for my GTI and boom the problems went away.. and yes if its cold out it was little harder to switch the gears but it doesn't take that long for the transmission to worm up, specially since is next to the engine.

Chris since i live in IL what kind of oil should i get for my car B7 A4 6speed MT?

[Tusin]

Thank you so much for all the responses. I was planning on doing a mix of MTL MT90. I have read our diffs take appx 3.5 liters (for a quattro 6MT). So maybe 2 MT90's to 1.5 MTL's?

The thing that started to concern me was that on Redlines website it states that it is not for use in Hypoid style transmissions. Which from what I have read ours are.

I have a half a bottle of Lubro-Moly GL5 that says it is good for manual gear boxes and hypoid setups. But has no mention of safe for yellow metals.

[Blarg]

The thing that started to concern me was that on Redlines website it states that it is not for use in Hypoid style transmissions. Which from what I have read ours are.

This would stop me from buying it, not worth the risk even though others have/are using it currently.

[Tusin]

B6 guys have been running it and haven't read that it has caused anything to fail. And at least according to tech sheets they have a hypoid based tranny too.

[Brillo]

I would be careful about using Redline MTL. Make sure it is recommended for synchro tranny with hypoid gears. Do not suggest using Redline MT-90. Also have not heard good things about the Amsoil product. I tried Mobil 1 75W-90 and liked it during the summer but when it's cold out shifting was a bitch. I have since found out that Mobil no longer recommends this for our manual transmissions. I switched back to what I believe is the OEM fluid which is Pentosin MTF-2. I think it's a 70W-80 and my trans shifts so much better now I can't believe I wasted $30 on M1. I am also under the impression that the Pentosin product is highly favored by the BMW folks.

[Tusin]

Hey Chris, would you mind chiming back in? Have you had satisfied customers with B7 A4's?

[ECS Tuning-Audi]

Hey there, sorry I don't work over-night!

We have B7 customers who use MTL and MT-90. In fact we have plenty of B6 and B7 customers running Redline products happily. We are looking into possible issues with Redline and Hypoid trannies, but to date we do not have any reported issues. I'll report back if we locate any issues.

[Tusin]

lol thanks Chris:) I did quite a bit of searching. And found a post from the user Diagnosticator over on the B6 forums. It is saved on my home computer. But he explained it along the lines of, that a hypoid system would LIKE to have GL-5. But it is more important to have the proper fluid (GL-4) for the syncros, for proper shift engagement, and not to damage yellow metals. I have to assume that is why Redline is saying "not for use for hypoid setups".

[ECS Tuning-Audi]

Hey guys, we've all read this wrong from the beginning: http://www.redlineoil.com/Products.aspx?pcid=7

It isn't for use in differentials with hypoid gears. It is cleared for transmissions in our VW/Audi applications. Sorry we didn't snag that little blurb sooner!

[Blarg]

Hey guys, we've all read this wrong from the beginning: http://www.redlineoil.com/Products.aspx?pcid=7

It isn't for use in differentials with hypoid gears. It is cleared for transmissions in our VW/Audi applications. Sorry we didn't snag that little blurb sooner!

Playing devil's advocate here, not saying anyone is wrong but doesn't the manual transmission fluid share with the front differencial that uses hypoid gears? Is it just better to use a GL5 for hypoid differencials but ok to use a GL4 if shared with the transmission?

[Tusin]

You are correct Blarg. But if you use GL-5 it will eat away at yellow metals (brass) in our transmission. But from what I have read there is no straight GL-4 that is "safe" for hypoid gears. But there is no GL5 that is truly safe for brass. Even though companies like Royal Purple says they are, there is a lot of evidence at bob is the oil guy that says other wise. Hmmmm, think would be a good question to post over there.

[chrislane31]

Motul Gear 300 is GL4 and GL5

[Tusin]

lol way to much information out there. GL4 can be used for hypoid gears that have small displacement of axles. So what do our Audi's have lol. Again I would bet good money that Redline is saying not for use with Hypoid gears to cover their butts.

I am going to do some research on Motul. I have heard nothing but great things. BUT I am not sure that "GL 4/5" is a true API rating. Maybe it just has less of the additives that eat yellow metals than a full GL-5 but more than a GL-4.

[positiv_rate]

Hey guys, we've all read this wrong from the beginning: http://www.redlineoil.com/Products.aspx?pcid=7

It isn't for use in differentials with hypoid gears. It is cleared for transmissions in our VW/Audi applications. Sorry we didn't snag that little blurb sooner!


Now I'm really confused [confused]

So in retrospect: short of buying the OEM Audi tranny & diff fluids, what are the recommended aftermarket products for: a) our manual transmissions and: b) our diffs?

Thanks for clarifying!

Carry on. [wrench]

[Tusin]

Again Redline MT90/MTL can be used for hypoid gear with small displacement. Not 100% sure what our system has.

But after doing more research, I have yet to find a user that uses MTL/MT90 that has had any issues at all. So I found a local dealer ($12.00 a quart) and did 2 bottles of MT90 and 1.5 of MTL. And it is performing freaking awesome.

[ECS Tuning-Audi]

Again Redline MT90/MTL can be used for hypoid gear with small displacement. Not 100% sure what our system has.

But after doing more research, I have yet to find a user that uses MTL/MT90 that has had any issues at all. So I found a local dealer ($12.00 a quart) and did 2 bottles of MT90 and 1.5 of MTL. And it is performing freaking awesome.

Awesome!! Thanks for the feedback. These threads are way more useful with followups.

[Tusin]

Thank you for the information as well Chris. Sorry I didn't purchase from you, but even finding a dealer up here in Alaska was surprising.

I think I gave you guys enough money for awhile a few years ago anyways:) (APR Stage 3, FW/Clutch setup and other stuff) for my old 1.8T

[ECS Tuning-Audi]

Yeah, I'll let it slide because Alaska is so darn far away! ;)