Poll: ATF used in w123 transmissions - PeachParts Mercedes-Benz Forum

JHZR2 · #1 05-07-2003, 04:14 PM

Please comment

JimSmith · #2 05-07-2003, 05:00 PM

Only have the 1998 E300D Turbodiesel that is an auto box, and I just had the auto transmission lubricant/fluid changed at 60,000 miles by the dealership. They use some special MB ATF with batwings and other mysterious ingredients that costs a lot. This subject has been discussed before, but the official word was the transmission was sealed for life. Life was not well defined and I suspected MB and I had a different view on what that should be, so I directed the shop to change the fluid. Cost just under $200, with most of the expense being the secret sauce. Will do it again at 120,000 miles, 180,000 miles, and so on, hopefully for a long time. Jim

Rick Miley · #3 05-07-2003, 05:03 PM

I did what Jim did, but at 75K miles. Had a tiny complaint at 90K miles and they rebuilt my transmission. Assuming I got a new dose of special sauce.

Sorry, my 123 has a manual and we're already been around THAT tree!

rwthomas1 · #4 05-07-2003, 07:32 PM

M1 is cheap and readily available. It made my trans shift much smoother in the morning when cold. Seems much smoother overall but that is not quantifiable. RT

edge · #5 05-07-2003, 11:45 PM

How expensive is Mobil 1 ATF vs. MB ATF?

autozen · #6 05-08-2003, 12:27 PM

After 30 years as a professional MB mechanic I still maintain that as long as you use a good quality brand oil, it doesn't make any difference. I've logged millions of total miles on cars using this philosophy. You'll go nuts trying to figure out which is best, and convince yourself you notice an improvement. I've discovered that the best way to tune up a car is to change the oil and wash the windows and vacuum. The clean car always ellicits a phone call from a customer stating how much better the car ran after I serviced it. It all comes down to perception. I've logged 320K on my 83 300TDT using whatever is on sale. No smoke, no oil consumption, plenty of power, and fires right up on cold morns before the glow light goes out. I just can't justify the extra cost and mental anguish involved in the search for the perfect oil. Anti freezes are another story because of the different base ingredients used in manufacturing.

Peter
Peter

lrg · #7 05-08-2003, 03:04 PM

I use RedLine ATF. No question it has helped the 123 shift smoother but it was a gradual improvement that took 10,000 miles or so to be fully felt. I'm guessing that the synthethic's higher detergency has slowly cleaned things up a bit. Not surprisingly the smoothness when cold is much better, not perfect but better.

#8 05-09-2003, 12:22 AM

I have a several SD's, TDT's and D's and I use regular ATF with a 2 year oil/filter replacement schedule. The cars have over 400,000 miles of our own driving with no tranny problems. I did use Quacker State until last year when a mechanic told me all the regular ATF's (non-synthetics) are all the same. I always thought they were like gasolines where one refinery cranks out the gas and the majors dump in their exclusive brand of additives. But I was told they are basically all the same so I bought the NAPA brand. I do not have the cold weather issues that require synthetics so it would be interesting to know if this is true. By the way, can these ATF's like Dextron/Mercon II be used successfully in the power steering system?

autozen · #9 05-09-2003, 12:30 PM

MBwerker,

Yes, you can use it in the power steering as well as in a stick shift tranny. I recently acquired a stick 240D with a bad clutch. I replaced the clutch ,but the shifts were still scratchy which led me to believe the PO had used the car too long with the bad clutch and wiped the synchros. I noticed the shift got better as the tranny warmed up which got me to wondering. I put the car in the air and checked the tranny fluid, and sure enough it had some kind of manual trans fluid that smelled like 90W. I drained and refilled with ATF and the shift is fine. Since Detroit iron has traditionally run with 90W in the sticks many people assume MBs do to and don't bother checking specs. I have drained 90W out of countless MBs. I wonder how many members in this group have 90W in their MB trannys.

Peter

CarolinaMBZ · #10 05-09-2003, 12:38 PM

It is my understanding that Mercedes specifically does not recommend Mobil-1 ATF be used in their transmissions. Not sure why this is, but thought I would pass it along. If anybody has more information on this, I would appreciate their passing it along.

lrg · #11 05-09-2003, 02:48 PM

Autozen,
Maybe you can confirm or correct an old explaination about using ATF in manual trannys that I once heard. I had a TR-8 with a five speed that specified ATF. I ran it with ATF but a mechanic once mistakenly put in regular gear oil and it was immediately noticable. I refilled it with ATF and asked a Triumph Guru why ATF was specified. He told me that more sophisticated transmissions have a pressurized oil system that keeps lighter oil (like ATF) circulating properly. Heaver oil is OK to use in those transmissions but makes everything work harder because they were designed for lighter oil. The more basic manual trannies that require heavy gear oil rely on splash lubrication and need the heavier oil to keep things covered. It is not a good idea to use ATF in those. This, I was told, is why you can't safely tow a car with the pressurized oil transmission because the pump doesn't run off the output shaft and towing any distance will cause gears to turn without proper lubrication. This all makes sense to me but maybe you can verify if it is in fact correct.

LRG

#12 05-09-2003, 03:40 PM

almost all of them are splash lubed, but some of them have synchronizing systems which are designed to work with lighter lubes, and if you put in the Extreme Pressure rated stuff, the synchros can't get enough grab in that slippery environment to do their job. Back in the '60s, we used to have a lot of trouble on Italian cars when the customers would put in some GL4 or 5 stuff when they were supposed to only use GL1, and then claim that the trans should be rebuilt on warranty because of bad synchros -- a good flush and drive around the block with #2 diesel in the trans and then refill with the right stuff or #30 motor oil would usually solve the problem.

In the early '60s there were a few Ferraris with pressure lubed transmissions (the ones with Laycock de Normanville overdrives, I believe) but these gave a lot of trouble-- they were originally designed for 90 weight and only had the pressure lube because the overdrive units required 30 weight engine oil (just as in the same units in Jaguars, Austin Healys, and Volvoes, which switched to ATF in later years).

autozen · #13 05-09-2003, 04:34 PM

Carolina,

MBZ probably has nothing against Mobil 1. They probably just didn't submit a sample. Mercedes runs exhaustive tests on fluids and lubricants from all mfgs that submit their products for testing. All those meeting specs are added to the recommended FLUIDS AND LBRICANTS LIST published by MBZ. If a particular product like Mobil 1 ATF isn't listed, it doesn't mean it isn't any good. It just means that for some reason it wasn't tested. I have a feeling the mfgs are required to pay for the testing which is why some pruucts don't appear on the list.

Lrg,

I believe Fimum has the right answers. I think MB transmixers are splash lubed like the rest. Manuals just always work and never go bad, so I don't spend a lot of time studying something I am never going to work on. Sorry. If I remember I'll look in my factory Mb manual trans manual to see if I come up with something different. I don't know why I ever bought the silly book; I don't remember ever opening it.

Peter

mbtjc · #14 05-11-2003, 06:04 PM

I don't own a diesel...but that shouldn't have any bearing on the transmission, right?

I did a search on Mobil 1 ATF and came across this post. I am getting ready to use Auto-Rx in my tranny, and then flush/change the fluid like they say to do on their site. Then the question is for me: which ATF to use?? I'd love to use Mobil 1 and smile thinking I am giving my car only the best....but close to $10/qt?!?!? I talked to my MB dealer, and they told me that they just go right down the street and buy generic O'Reilly's Auto Parts Dexron ATF. A little over a buck per qt.

I guess if the dealers use plain ol' ATF (except for the new ones that actually require the fancy stuff obviously), I cannot justify spending an extra 7 or 8 bucks per quart.

I think I'm gonna agree with Peter....it's all in one's head.

Any thoughts?

ericnguyen · #15 05-11-2003, 08:41 PM

mbtjc:

Do not waste your money on Mobil 1 ATF unless your car's transmission have hard shifting and/or flaring problem during cold weather. Also, instead of using Auto-RX (another $5 or $10 ?), you can just buy Valvoline MaxLife ATF (about $1.8 per quart) which has cleaning, sealing, friction modifier ... additives. Valvoline is a brand-name company and I've had great results with their products.

Eric

View Poll Results: What ATF do you use in your car?
Mobil1 ATF	10	37.04%
Quaker State Dexron	1	3.70%
AAMCO ATF Dexron	0	0%
Mercedes-Benz ATF	2	7.41%
Another ATF explicitly stated to be a Dexron II or Dexron fluid	14	51.85%
Voters: 27. You may not vote on this poll