What is the thought on using a high-quality (Mobil 1 Synthetic ATF) versus the OEM fluid in my wife’s 1999 ML320? Definite no-no, it may be ok, or there’s no difference?

I have used the Mobil 1 Synthetic ATF in my 1984 300SD with no problems, but not sure about the newer transmissions.

Thank you.

Why risk it? You can easily get the MB fluid on-line for less than $12 a liter with free shipping. My dealer wants like $18 per liter. Simply ridiculous markup above the MB list price.

I will tell you that I have found a new MB indy for my new to me '97 S320.
In business at same location for 30 years. Guy is a factory trained MB mechanic.

His opinion is that synthetic transmission fluid is fine. That's all he has used since 1996 when the tranny's requiring MB fluid came out.

I still elected to do my own tranny service with the genuine stuff.
If I let him use his synthetic fluid and the tranny crashes, I guarantee
he is not going to fix it for free.

Steve

Exactly, for such a high dollar item as a transmission why risk it. Having said that the Mobil 1 Synthetic ATF is prbably fine but I wouldn't put it in my ML.

I did my own trans service about 2 years ago now. I used about 7 quarts of Mobil 1 after draining the pan and the torque converter. I also changed the filter and added the pan magnet.

The trans was acting a little funny, hanging up in the higher gears while coming to a stop, and skip shifting where it would miss a gear on the up shift sometimes. Just occasionally, mind you.

It has worked flawlessly (knock wood) since then and I expect to change 7 quarts again at about 30,000 miles on this oil. That will be at about 150,000 miles total, on the origninal transmission.

I also used Mobil 1 ATF in the transfer case at the same time. On a recent level check, I noted the oil was pretty dark so I changed it again.

Mobil 1 75-90 gear oil in both differentials. The front one was leaking at the pinion seal when I got the car and the differential was almost dry. (The previous lady owner was meticulous in having it serviced and no one checks this???) Since going to Mobil 1, the leak seems to have slowed as time goes by. I wipe a few drops off the cross member but nothing hits the driveway.


If Mobil 1 made brake fluid, I would have it in the brake system, synthetic or not.

REgards,

Jim in Phoenix

For what my opinion is worth, synthetic is the way to go. I personally prefer Amsoil products (they have been doing it longer than anyone else and have the widest array of products) but the Mobil is probably fine too. Price wise, are you kidding me on the $18 per liter at the MB dealer?! I order the Amsoil at dealer cost and it's around $6 per quart shipped. Here again, personal preference but I've been using the Amsoil in everything I own (including air and oil filters, oil, trans fluid, grease, gear lube and more) since 1987 with wonderful results.

I have a 2002 ML 320 120 000 km
At how many km intervals should one change the ATF oil and with what now? synthetic/conventional mobil or Amsoil?

Is there more than new filter, a magnet and oil is there soming else required or one should do?

Mercedes initially declared the trans was sealed for "life" and the fluid need not be changed. Life became a question of luck for some MB owners with total trans failures as early as 75,000 miles. Recently, MB has revised it's thinking and is now recommending a trans fluid change every 37,500 miles, which conicides with some letter service in your maintenance folder.

The recommended trans fluid has a MB part number and is definitely a synthetic product, some say made by Mobil to MB specs. There is no dipstick on your trans, it is a service part now. You can order one or you can use a piece of flex like an old speedo cable. It is somewhat critical to restore the oil level to it's normal level at fully warmed conditions.

When I did my 98 ML (see my note above) I drained the trans and the torque converter, getting out about 7 quarts of the 11 or so in the system.

NOTE: I hear that some models do not have a torque converter drain plug. This limits the amount of fluid you can change to less than 4 quarts. I plan to change my fluid at about 30,000 miles but I would cut that to 15,000, if I could not drain the torque converter. Some are experimenting with opening the lower cooling line going to the radiator. You can run the engine and pump until the fluid stops coming out. Probably a small risk of trans damage but it's an option.

DO NOT let anyone talk you into a trans flush. Reverse flushing that claims to clean the filter may make a flow path, but will not be satisfactory substitute for changing the filter.

The pan must be removed to change the filter, and add the magnet, and the flush job normally does not include a filter.

Regards,

Jim in Phoenix

The fluid level is CRITICAL. It must be "read" with a special "dipstick" and the oil must be at a certain temperature.

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Jim

MBUSA says it's made by Shell and Fuchs.

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W163.154, M112.942, 722.662, ZF.970.402

I have a 98 ML with 120K. As far as I know the fluid has never been changed. I called a local trans shop and they recommend that I keep runing it as is. Not sure if this is good advise. He said that often a high milage trans will have problems after service is done. I have had this experience with other vehicles in the past. Any suggestions?

ABSOLUTELY, get it changed! You are driving a time bomb NOW! My MB service guy says the average trans life on these 5 speeds is about 125K. The trans people claim that new fluid will clean places that may open up clearances to the point of failure. I think that they are afraid that any failure after their service will come back at them so why chance it for a few bucks profit. The dealer will charge you over $5000 to put in a new trans and programming.

The dealer will do it for you, if no one else will. It is fairly easy to do as there are drain plugs on the pan and the 98s have a drain plug on the torque converter. You have to buy a service dipstick (or make one) to measure the current oil level when hot. Read the archives. Definitely change the filter and add the magnet, part numbers listed elsewhere.

Regards,

Jim in Phoenix
146,000 and counting on my 98 ML320

FYI, I just spoke to MBUSA customer service, which said on the ml320 from 1998-2004 MB does not recommend changing the tranny fluid at all.

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87 300e (white/black; amg body kit)
88 300ce (red/cream; amg body kit)
93 300ce cabrio (white/blue/blue top)
93 300ce cabrio (black/grey/black top)
98 ml 320 (totaled @ 137,000 miles)
99 clk320 (black/grey/black top)

The only reason to not change a lubricant/working fluid in any hydraulic system is if you have some type of renewable filtration system (a pan filter definitely is not a decent filter system). I had the fluid changed last year at 110K on our 98 ML320, the old fluid was black and no doubt in need of changing. Transmission smoothness no doubtedly improved afterwards. We are up to 125K now, hoping to get another 12 months of use out of the ML before we sell it and get a 2003 or 2004 ML.

Had my MD dealer do a "Transmision Service" at 150,000KM which included fluid and filter. Will do again soon at 250,000KM.... and hope to do it again at 350,000KM original transmision cross my fingers . Drives smoother after the service no question.

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1998 ML 320
BIG Sound

My 98 ML trans is shifting a little rough sometimes. Has 120K. I'm going to change the fluid and filter using Mobile Synthetic etc. Any pointers or suggestions. Is there a specific torque for the cover bolts. Does anyone know how to make a trans stick. The shop version is $80.

Thanks
HEH