How often do we change the MT fluid in our 6SPDs? I asked my dealer, they said it never needs to be changed?!

 

I've heard that for most cars (manual or auto), their transmission fluid doesn't have to really be changed. Nothing ever happens to it, but my mechanic said that if you're really superstitious about things...change it every year or two years. Just make sure whatever you put in is or is near highest quality you can get.

 

They say "never has to be changed" because MB says their transmissions are "sealed" and have "lifetime fluid". By "lifetime" they mean if the transmission fails at 80k, then the service life of that fluid was 80k miles. Get the idea? Most dealers won't change the fluid even though the customer is WILLING to pay money for it. They'll have to find a dealer who is willing or go to an independent shop who works on Euro cars.

Changing the fluid is a good idea as there might be shavings, etc in the fluid from the time being in service. I had the trans fluid on my folk's '99 ML430 at 60k because shifting was a little more harder and noticible (not butter smooth as before). Spent $150 for the job at a MB indy shop and the shifting was back to smoothness. The old fluid was very dark and brown compared to the new stuff that was put in. Its cheap insurance.

If a transmission has much higher miles, like 90 or 100k without a change, even a lot of indy shops recommend not touching it because there might be filing materials packed in places inside the tranny that could be "helping" the transmission (kinda like keeping it together) and if the fluid is flushed, those filings could be washed away and cause the transmission to fail pretty soon after the fluid is replaced.

I'd say 60k is a good point to get the fluid changed, really, its cheap insurance to change it or more of a piece of mind. On a manual unit (at least for the Audis), it should be pretty simple to change it yourself...should just be a drain and fill plug. There is no magnetic pan to deal with as on the Auto transmission units (again, MB might be a little different). Might want to check out doing it yourself if you're a DIY kinda person. It saves a lot of money and gives you the satisfaction of changing it on your own

 

I've done mine at 75,000 kms (46,600miles) It isn't expensive, just get it done. Another thing to think about is your fluid in the rear diff.

 

Most manual transmissions have a magnet attached to the drain plug. All the shavings are usually stuck to it and not circulating throughout.

 

Thanks for all the advices. I talk to the parts department in MB dealer, they don't even have a price for the MB manual transmission fluid, because it's so rare, they don't even keep it in their inventory. I think I'll search around and see if any independent shop knows how to do it.

 

Are you a DIY kinda person? If so, its pretty simple for a manual transmission as there is no pan to drop, usually just a fill and drain plug. An automatic transmission has a pan that needs to be dropped which makes it a little more difficult. I just changed mine in a little over an hour yesterday.

Jack car up (must be even so use 4 jackstands)
Make sure you can loosen the fill plug FIRST otherwise if you drain the fluid out and cannot get that fill plug open, you're toast
Loosen drain plug and drain all the fluid out (if someone with a Bently repair manual can verify for you how many quarts)
Re-secure drain plug after all fluid is drained
Take out fill plug and use a suction gun (available at Autozone for about $10) to refill transmission with MB Synthetic Transmission fluid
Tighten fill plug
Lower car
You're done! Congratulate yourself for saving an hour worth of labor from dealer

 

Yeh, go with the DIY and contact Royal Purple to find out which fluid is best for your car.
I noticed they are a site sponsor now as well.

Other people have had excellent results with their fluid.
Typically, you'd want to change it every 50K miles or so.

Don't bother with trying to buy the oil from the parts dept.
It's likely it's not rare, just that they buy it in barrels, not
consumer sized containers, just like the motor oil etc.

You can also use one of those drill operated pumps to put the oil in.
Just got mine! Haven't used it yet, but it looks very handy!
Look for "sureflow drill pump" on West Marine's website or other places as well.

Capacity of the tranny is listed in your manual,
and like the man says it's an easy DIY.
Drain and fill.
No filter, no gaskets.

 

I guess it's a simple DIY job, is draining alone gonna get all the contaminants out? Doesn't a flush clean out the contaminants much better?

Now if only the weather will get back up to 70+ then I guess I can do a write up or something. Too cold to work in the garage or on the driveway at the moment. It's still like 30s and 40s in Chicago

 

Eh, weather isn't a factor It was 45 in Boston yesterday

I have been told that many manual transmissions can use 10w30 motor oil to do a flush, especially if its your first change. Fill with 10w30 and run it for a bit then drain and put the synthetic stuff in. I replaced my Audi OEM synthetic fill with Motul 300 gear oil (syn), highly recommended stuff by car enthusiasts. Royal Purple is another, as mentioned above.

 

Now if only I know what kind of transmission oil to put in, the owners manual doesn't specify any particular gear oil (for example, 75w-90, etc..). Just says "MB manual transmission oil"

 

Hey GDawgC220,
Haven't posted in a while...but on the #3 post of this thread (which is also your post)...thanks for correcting me...I actually had no idea! Well I guess I should consider changing tranny fluid soon...I'm about to hit 40,000...I wanna make sure to get it done at shorter intervals (just my way of doing things)....

but what I am stuck on, along with BabyBenz6spd, is what type of transmission oil to put in after draining the old fluids out .

Thanks again for all the useful info GDawg...my daily commute hit 101,000 miles...never did a tranny drain nor flush...you think it's too late to do anything about that since you did mention that some "filing materials" may be in the tranny oil?

Btw...both my cars are auto's.

 

Yeah, MB likes to be vague with their oil/fill info. Guess they try to deter people from DIY and go to the dealer I used 75w-90 gear oil for my 6-speed unit, which is equal to if not a little better than OEM Audi stuff they use from factory. Lemme see if I can find out what fluid the MB 6-speed units use.

 

No problem

As for your transmission, the fluid for an Auto tranny needs to be set at a specific temperature when filling vs the manual transmission where its just straight fill, no need for a specific temp. I believe MB has a specific Auto transmission fill they require (lemme see what I can find for you).

How is the car shifting? Rough? Still smooth? While the drain plug might be magnetic, it does not attract every bit of metal shaving to it, other shavings and filings will get packed into other areas of the transmission. Some people who have had transmission fluid changes at high mileage (90k+), their transmissions failed a short time later. Now, related to the transmission fluid change? Might be...talked to a few mechanics who pretty much agree that with high mileage, usually better to leave the fluid in there as those filings and shavings may actually be helping since they're packed somewhere and not floating around. When you change the fluid and those shavings/filings get dislodged and not all removed then the remaining are free and floating around when you put that new fluid in. Once you get those shavings floating around that are not stuck to that drain plug area, its not good for the gears.

I would say if your transmission is shifting fine and is not rough or jerks, I'd say leave it at that mileage.

 

So here is what I've found...

In the past, MB had recommended the use of ATF in the Manual Gear Box. But during a search, someone had posted that the new Manual fluid that MB sells is now a gear oil 75w-90 (whereas they previously said no gear oil) in their bottling (part #001989 26 03). That being said, a bunch of people been running 75w-90 oil for their manual gear boxes which has been fine. Royal Purple has gotten pretty good reviews for their Max Gear oil, which you can buy online. I'm not sure what the capacity is for the MB 6-speed, that might be mentioned in your manual.

http://royalpurple.com/prodsa/mgeara.html

 

How many times have I've said in these forums
"Contact tech support" for either Royal purple or
Redline.

THEY will tell you what to buy. I once bought what I thought was the right Redline oil for my 86' Bertone X19, THEN called and was told, oh no, wrong stuff.
Had to to drain it and refill it. The stuff is expensive, not something you want to do twice. Just check their websites for the ph #, and just call and ask.
Why does no one listen to me on this?
Geez.

 

I just e-mailed them, and thanks bro~ me--> <--you

 

I just had a 60,000 mile Service B done ($498) at MB Manhattan, NY. At the same time, I asked them to do a transmission service on my C230 SS manual. My invoice is dated April 3, 2007. They performed a power flush of the transmisison and torque converter and changed the filter and replaced with synthetic fluid. It cost $122 parts and $164 labor. I know it could have been done cheeper if I were handy, but I am not. Also, I do not have a trusted service place, either. I think in SoCal you have lots.

As to timing, my transmission was a bit notchy and I just felt like it could not be a bad thing. It really does feel better.

By the way, I asked them to check my shocks as they felt a bit off. I was told they are fine. MB Manhattan is really very good.

I hope that helps.

 

My invoice from MB says they used synthetic fluid with part # 001-989-21-03-10. I hope that helps. Whatever you do, do not put the wrong stuff in your transmission.

 

cool, thanks!

 

I got a response back from Redline oil, they recommend using "Redline MTL" for my 2k5 c230k 6spd

I'm still waiting for a response from Royal Purple.

 

Ok, this is the exact response I got from Royal Purple,

Quote

"Danny,

Was unable to find any information on the fluid as Mercedes keeps their
fluids under the radar. I will continue to look and see if I can come
up with anything, but as of now Royal Purple recommends you continue to
run the factory fluid.

Have a great day."

 

Simplest and probably safest solution now is to go to the dealer parts counter and buy the fluid they "spec" for your transmission and do the change.

 

so all these people recommending ROYAL PURPLE....

what are they using ????

 

I believe those who are using Royal Purple are using this product from them:
http://royalpurple.com/prodsa/matfa.html