atf or mtf??

[sandman1]

i've been reading alot about replacing the tranny fluid in my 99 z3 2.8 w/manual trans. seems like most use the redline d4 atf. but what about the redline mtf? wouldn't mtf be better for the manual tranny? im confused

[Robstah]

Lift the car up and there should be a badge on the transmission itself, telling you which one to use. If I remember right, I ended up putting some ATF in mine.

[Gibber66]

Do a search, but if I recall correctly, the most recommended fluid is a mix of equal parts Redline 75W-140 with Redline ATF. Some have used as low as W-90, but usually with some noise or shifting problems. Hope this helps!

Cheers,
Gibber

[A.LaPole2.8L 00]

What's the electronic valve thingy?
Picture?

[Car54]

This month's Roundel, Satch recommmends MTL for the 323 and excludes the ATF, I'm not sure if that's a Getrag or ZF...I emailed Satch about the M's.

[brm]

Please post what you find out. I strongly suspect my car still has the original gb and diff. fluids, and intend to replace them this year.

[awdonald]

I use MTL...just because.

It works fine...Z3 M Coupe

Cheers,
Alan

[z123]

How would you know when to replace your transmission fluid? are there any symptons that would indicate it?

[Car54]

This from Roundel:

Craig,

Thanks for your interest in Roundel Tech Talk.

I prefer not to use ATF in any manual gearbox -- ZF, Getrag, or otherwise. MTL is the superior product for gearbox lubrication. See attached document.

Regarding differential oil viscosity, go ahead and post this on your forums on my behalf:

There is much confusion on Internet forums regarding the BMW-recommended oil viscosity for limited slip differentials. Here's the skinny: BMW is notorious for mandating use of BMW Special Lubricant X or else (insert parade of horribles here). Then, before too long, BMW Special Lubricant X is no longer available, having been replaced by BMW Special Lubricant Y for the new cars. BMW Special Lubricant Y is then magically approved for use in older cars -- the same ones that would have self-destructed without BMW Special Lubricant X.

So, to figure out which lubricant is correct or appropriate for which car requires one to have a certain history with BMW, so that you know what the old specification was, before it was replaced with the new specification, the latter being tailored to the new cars. People without this historical perspective read something I wrote about diff oil and think I'm wrong, but I'm not.

In the case of limited slip differential oil, the BMW-specified viscosity was 75W-90 for decades until they came out the M Variable Lock differential in the E46 M3, whereupon "BMW Special Lubricant Y" was introduced. Today, all the modern M cars have versions of the M Variable Lock differential:

E46 M3
E90/91/92 M3
E60 M5
E63/63 M6
Z4 M roadster
Z4 M coupe

With the advent of the M Variable Lock differential, BMW went to 75W-140 (presently Castrol SAF XJ), and did away with the factory 75W-90 limited slip differential oil. Once again, the new oil was magically approved for the older models.

The E36 M coupe does not have the M Variable Lock differential (only the models listed above do), but it does have a limited slip differential, so the viscosity specification for your car is 75W-90. You can certainly use 75W-140 in a non-M Variable Lock differential, but you cannot use 75W-90 in an M Variable Lock differential.

BMW has a different oil viscosity specification for open differentials (non-limited slip), and it has always been 75W-90 (presently Castrol SAF XO). Open differential oil cannot be used in limited slip differentials because it does not have the friction modifiers required by the limited slip mechanism. However, there is no problem with using limited slip differential oil in an open differential -- the open diffs don't mind those friction modifiers at all.

Now, in my work I long ago realized that the more choices you give people the greater the chance that they'll get it wrong. So, when recommending aftermarket differential lubricants in print, you'll see me advocate Red Line 75W-90 for all BMW differentials (open and limited slip) except the M Variable Lock differential, which should get Red Line 75W-140. That is the simplest I can make it and even with only two choices, people still get it wrong.

But like I said, 75W-140 isn't going to hurt your diff. If you lived in an extremely cold climate, I'd advise you to go back to 75W-90, but that's not a concern in Virginia.

I hope this clears things up.

Best regards,

Mike Miller
BMW CCA Roundel Magazine Technical Editor
techtalk@roundel.org
auspuf2002@aol.com

[bmellott]

get the correct stuff from BMW, done. change every 30K
I did the RP in the tranny once (there are 4 potential different types dependant on the tag on it, yeap called RP to make sure)) I did not notice any better shifting.

[Car54]

More:

Red Line MTL vs. Red Line D4 ATF: Which to Use


Background

In case you’ve been living under a rock or you are now driving your first BMW, let’s introduce you to Red Line Oil.

Back in the early 1980s, BMW enthusiasts (enthusiasts and serious drivers comprised the bulk of BMW owners back then) had long since digested the notion of worn out second gear synchronizer around 60,000 miles and the need for a gearbox rebuild. Same for differentials, only at later mileages. And the Borg Warner automatic transmissions had a service life of about 40,000 miles.

Then, real quiet like, some people started to experiment with newfangled synthetic oil oils from a tiny refinery in California that sold their own brew at what were then incredibly high prices. It did not take long before we saw that gearboxes using Red Line MTL (Manual Transmission Lubricant) did not wear out synchronizers, bearings, or anything else. Almost better, you could put MTL in a gearbox that crunched second gear, and in about 500 miles, the crunch would go away. Most people did not believe it until they saw it with their own eyes – I didn’t…until I did.

Then we tried Red Line ATF in the Borg Warner slushboxes, and lo and behold, they stopped breaking – sort of (it’s still an automatic).

Red Line Oil burst on to the pages of the BMW Car Club of America’s Roundel magazine, and it has never left. MTL is mother’s milk for manual gearboxes, and it wasn’t long before other Red Line lubricants became popular as well – 75W-90 Synthetic Gear Oil for differentials, ATF and later, D4 ATF, motor oils, fuel system additives, CV joint grease, etc. We were hooked.

BMW, being BMW, has disavowed Red Line Oil, and they will regale you with horror warnings. Twenty years of empirical evidence before our very eyes contradicts BMW on these points. Moreover, BMW is rather infamous for mandating use of “Special Lubricant X” or else…insert parade of horribles here. Then, before too long, Special Lubricant X is no longer available, having been replaced by Special Lubricant Y for the next model year cars. Of course, Special Lubricant Y is then approved, magically, for older cars.

Finally, long-term experience with BMW familiarizes one with a somewhat elitist “not made here” syndrome – there is a culture at BMW that says if something did not originate internally, it cannot be good. However, there is a culture among BMW enthusiasts that says we were tired of rebuilding drivetrain components. As is often the case, engineers continue to debate cause and effect long after those of us who actually work on cars learn to trust the empirical evidence before our eyes.




What Red Line Oil Recommends

Red Line Oil (www.redlineoil.com) recommends different products depending on the BMW gearbox in question, which depends a great deal on the model year BMW in question. For older gearboxes, Red Line Oil recommends MTL, for newer gearboxes, they recommend their D4 ATF product. Where is the cutoff? That is the $64,000 question to which no one has a definitive answer. This is where it gets complicated, but unduly so. Let me explain…

In the old days, Red Line Oil advised that BMW manual gearboxes have either a green label, a red label or no label from the factory. For green label cars, Red Line recommends their MT90 manual transmission lubricant. Red label cars get D4ATF. No label cars get Red Line MTL.

Today, however, BMW gearboxes have no label and Red Line recommends D4 ATF. Also, those labels tended to fall off.

Cold Shifting Concerns

BMW used an ATF product in some manual gearboxes. The reason for this is probably that ATF has nice cold weather shifting qualities, and probably cuts down on customer complaints about “hard shifting when cold.” But it is normal to have to shift gently when a gearbox is cold.

ATF is great when you’re a synchronizer, because it is a friction enhancer that helps synchronizers do their job. ATF also flows nicely when it is cold. However, when you’re a bearing, ATF isn’t exactly the ideal lubricant, especially at very high temperatures. In fact, most ATF is a terrible bearing lubricant.

I note that Red Line MTL also has excellent cold weather shifting and flow qualities.

Red Line Oil also espouses the cold weather shifting qualities of their D4 ATF product, a synthetic Dexron IV product. They have admitted to me that their D4 ATF recommendation is also a nod toward BMW’s warranty.

Today, BMW uses a product they call MTL-LT-2 in manual gearboxes. This is not an ATF, but a synthetic gear oil. It smells and feels a lot like Red Line MTL but it is not red in color. I think MTL-LT-2 is an excellent lubricant, but I still recommend changing it for break-in at 1,200 miles and every 30,000 miles thereafter.

Another factor, though, is that while any manual gearbox with any lubricant requires a deft hand until it warms up, not all drivers can be trusted to employ that deft hand, so D4 ATF becomes the universal recommendation.


What the Pros Use

Legendary BMW gearbox rebuilder Jim Blanton has been putting these units together for over thirty years, and he will use only Red Line MTL – in fact, he fills each rebuilt gearbox with MTL before shipping it.

Jim Rowe of Metric Mechanic is also a legendary BMW gearbox rebuilder; he uses only Red Line MTL just like Blanton.

Brett Anderson of Koala Motorsport is perhaps one of the best BMW technicians and drivetrain rebuilders in the U.S., and he uses only Red Line MTL.

As a humble but hardened do-it-yourselfer and car writer, I have used MTL extensively, and have had nothing but extraordinary long-term experience with this fine product. I have also used D4 ATF in manual gearboxes. Performance-wise, I can’t tell the difference. But I don’t have long-term experience with D4 ATF. My personal feeling is I’d rather use MTL.

Lightweight Flywheels and Gearbox Rattle

Before BMW went to the dual mass flywheel, you could hear a little gear rattle with the shifter in neutral and the clutch pedal out. This is normal vehicle function in Bimmers with single-mass flywheels. BMW went to dual mass flywheels in part to eliminate this noise. Problem is, dual mass flywheels are very heavy and cannot be resurfaced at clutch replacement time. So, some BMW enthusiasts install a single-mass lightweight flywheel, usually an aluminum unit with a replaceable steel friction surface. Gearbox rattle in neutral can return to these cars. If you want to run Red Line MT90, which is slightly heavier than MTL, this gearbox rattle will be reduced in most cases.

My Wife Can’t Shift; I Have An Automatic. Can I Change the “Lifetime Fill” to Red Line D4 ATF?

This subject merits its own article. E-mail Tech Talk if you want to read it.

What About the BMW Warranty?

As for the BMW New Vehicle Limited Warranty, in my opinion and experience, it is highly unlikely that you will experience any manual gearbox failure within the warranty period. It is even more unlikely that any such failure would be lubrication-related regardless of which product you use – BMW factory fill, Red Line D4 ATF, or Red Line MTL.

If a dealership can plausibly deny any warranty claim, chances are they will do so; they have a “warranty index” to protect and they are not in the business of selling warranty work. If you do experience an internal manual gearbox failure and the dealer discovers non-factory-fill lubricant, they may deny the claim regardless of what product you used – D4 ATF or MTL. I believe it would then be incumbent upon BMW to prove that the lubricant you used caused the failure in question, which, as a practical matter, would be a very tall order even in the unlikely event it were true.

Anticipating your next question, yes, Red Line D4 ATF looks a lot like BMW’s factory fill ATF, but BMW doesn’t use ATF in manual gearboxes anymore.

Conclusion

Fill your gearbox with whatever you want. If you want to know what I use, it is Red Line MTL, except for those few “green label” cars, in which I do use MT-90 – which I believe is the Getrag 280 in the E28 and E34 M5, and E24 M6.

However, at the same time we have to recognize that cooler ambient temperatures require any manual gearbox to be treated with deference until it warms up. Car manufacturers, technicians, and lubricant manufacturers cannot depend on every driver to do that. Some people treat the shifter like it was a certain body appendage, whereas we should be treating it like it was a Faberge Egg – regardless of temperature. That is why we have manual gearboxes filled with automatic transmission fluid – because it shifts better when cold and we can’t trust all drivers to treat the gearbox right.

Of course, I’m obliged to say that no warranties are given or implied. You’re reading my opinion, and regardless of how well founded it may be or how many professional BMW technicians may agree with me, “Your mileage may vary.”

(c) 2003 Mike Miller

[extra330]

FWIW

A few weeks ago I did the tranny fluid in my 99 Z3M and tried Royal Purple syncromax. It feels great and shift quality is much improved over the 59Kmile old OEM fluid.

Mike

[HEMIkiller]

Outstanding write up and thank you for the clarification. I'm an old "Muscle Car" mechanic and just for the record I'm running Mobil 1 75 W 90 full synthetic in my gear box and diff. My car is stored on the shores of Lake Erie and only comes out in fair weather...

Tim

[2kredz3]

Amsoil MTF ---> for the win

[sandman1]

thanks, all. think i am going with the redline mtl. i would go for the bmw stuff but it is only available in gallon size and over $100.

[Car54]

http://synlubes.com/ is a great place to get lube if you don't have a shop nearby...


Don't forget to get a sta-lube pump....Advanced Auto Parts carries them for like $6.

[steveyb]

i have a 99 m roadster (24k miles), I have used both red line atf AND royal purple MTL synchromax. Being that i have used both in a 4 month span of time last summer I have a pretty concrete answer for you!
Royal purple MTL synchromax(non atf) shifts WAY smoother than the stock fluid and the red line atf. As far as the rear diff, Royal purple 75-90 is superb .
A few guys that i know that track there m's ALL use Royal purple mtf.
WHY? WELL Because experience for individuals that can change fluids easy and frquently has lead to a conclusion of Royal Purple.
Many on this board are stuck on redline because of the "name" when in actuality, there is a better product for our cranky trannies!!! Royal Purple!!!

Take care

[sandman1]

how about for daily use? isn't rp more for racing?

[steveyb]

No way! if its better for racing and the harshest conditions, then why wouldnt it be better for lighter use?
If it has performed superior on the track and street, then it will be gold for a non track user. TRUST ME dude, RP is the way to go!
Been there, used all, and RP outperforms.
Dont fall into the "redline" marketing" name trap that many others have! redline is great, and i am not bashing it, BUT your car will be healthier and happier with Royal Purple! Promise

[Ian 2.0]

I have RP on my 2.8 tran & diff and plan to use Redline on my MC. I want my own personal experience to be the judge.

[osborni]

What the Pros Use

Legendary BMW gearbox rebuilder Jim Blanton has been putting these units together for over thirty years, and he will use only Red Line MTL – in fact, he fills each rebuilt gearbox with MTL before shipping it.

Jim Rowe of Metric Mechanic is also a legendary BMW gearbox rebuilder; he uses only Red Line MTL just like Blanton.

Brett Anderson of Koala Motorsport is perhaps one of the best BMW technicians and drivetrain rebuilders in the U.S., and he uses only Red Line MTL.

No way! if its better for racing and the harshest conditions, then why wouldnt it be better for lighter use?
If it has performed superior on the track and street, then it will be gold for a non track user. TRUST ME dude, RP is the way to go!
Been there, used all, and RP outperforms.
Dont fall into the "redline" marketing" name trap that many others have! redline is great, and i am not bashing it, BUT your car will be healthier and happier with Royal Purple! Promise

A few dudes using a product don't compare to the number of trannys a builder looks at and sells. Just because 1 or a few have success doesn't translate to a wider population.

That said. RP MTL gives me crunchy syncros when cold though RL MTL does not.

[Gibber66]

These test results were enough for me to go with RP. Other posts boast of improved gas mileage due to lower friction loss. Thoughts?

[raubritter]

I experienced a 2-3 mpg increase switching to Royal Purple (engine, tranny, diff), plus the car seemed to run stronger. Shifting felt fine cold, hot, whenever. I always double-clutch+rev-match so can't speak for synchro effects...

Though I am curious about Redline after all these builder endorsements. Also curious about Lubro Moly, which Bavarian Auto claims is 'better' than Redline and is recommended by BMW in Germany or some such. Anyone use that stuff or know anything about it???

[raubritter]

By the way, that compao that Gibber66 posted is the only independent test like that I've seen. I wish Car and Driver/etc would do oil comparos every once in a while... I mean, oil IS sort of important to car enthusiasts