Transmission fluid replacement schedule - PeachParts Mercedes-Benz Forum

jhodg5ck · #1 12-15-2006, 09:43 AM

Well, their cost to replace one of these transmission is most @ least in the 5-6K range.. I'm sure they are making their usual brutal mark up on the transmission and they have some wiz that can knock it out in a matter of a couple of hours.

Be that as it may, I change the fluid in my 96 S600 every 15-20K (doesn't' get driven much)...costs me 110-120 even w/ my discounts but I'd Much prefer that then R&R'ing that bloody box.

Jonathan

Gilly · #2 12-15-2006, 09:51 AM

Right, but look at the economy of scale or whatever it's called, in others words recommend servicing them ALL every 30K vs replacing relative few of them. On a PERSONAL level yes if I thought it would really keep the transmission from failing (which I contend it WON'T), sure change it. From MBs outlook, they would stand to make MORE money by recommending the fluid change.
Gilly

jhodg5ck · #3 12-15-2006, 10:07 AM

They would stand to make more, but they also open them selves up to a lot more liability.. Better to call it life time fill and replcae it once every 100K I would think.. I'm sure they have had their share of techs messing up a trans fluid change only to have the customer come back demanding they replace their transmission.

Way I see it why not give the transmission best chance possible of lasting.. Hell, I know people who don't change their engine oil for 40-50+k..their engines all make it to 100,000 miles so what's to say we shouldn't all adopt that interval?

Jonathan

Gilly · #4 12-15-2006, 10:41 AM

Quote:

Hell, I know people who don't change their engine oil for 40-50+k..their engines all make it to 100,000 miles so what's to say we shouldn't all adopt that interval?

Well now your just being stupid

Gilly

waybomb · #5 12-15-2006, 11:23 PM

Well, my good for life tranny in the ML lasted its life - about 150,000 miles worth.

Trans fluid black - like black paint. Little needle bearings in the pan. Rebuilt tranny + torque converter + shipping = $2295.00. I just finally got to installing it. Got fluid from the dealership at $7.75 per qt. Flushed the cooler and lines. I used 20 liters total, including wasting a bunch in the flush.

I knew better. I should have changed the fluid every 30k or so. I am changing again in 1000 miles just to be sure, then every 30,000. You say it's a waste? Let's see, less than $100 every 30,000 or $2,400 every 150,000.

You wanna believe MB on forever fill, fine. I learned something different. In all my years of driving, I have never had a trans go bad.

Gilly · #6 12-15-2006, 11:36 PM

Prove that changing the fluid every 30K would have saved it.......
There's graphite in the friction discs, it turns black right away, comperable to say engine oil in a diesel. Just because it's black doesn't mean it's dirty, it's a sealed transmission, no "dirt" gets inside. That's same as saying green beer is bad on St Pattys Day.
Gilly

Gilly · #7 12-15-2006, 11:41 PM

The Color of Money:

We have been conditioned to judge the quality of the transmission fluid based solely on it's color and smell. We have no way of judging the frictional quality. The rules have changed. The bright red color that we are all used to seeing may not be what you see when you look at the ATF in a 722.6. The reasons that the oil looks differently are as follows:

1) The oil may appear dark red due to the graphite material that the friction discs contain. This does not change the characteristics of the oil. Do not change the oil or transmission if the oil appears dark red or even if it has a yellowish tint to it. The color will change with time and temperature. As of 10/97, the manufacturer of the oil has agreed to put more red particles in the oil.

jhodg5ck · #8 12-16-2006, 06:43 PM

Quote:

Originally Posted by Gilly

Well now your just being stupid

Gilly

Based on your logic I don't feel as though I am..I'm just carrying it through to another aspect of drive train.

I find it odd that once MB started to offer long term warranty's their cars went from requiring regular/routine/all encompassing service to needing essentially no service.

The physics of the transmissions inner workings didn't change applicably, and while synthetic fluids are a vast improvement I do not believe they are that good. Plus, these new transmissions w/ more gears go through Far more changes their our old boxes and do said changes smoother w/ more slippage then a firm shifting box thus generating more heat and wear on the clutch discs.

I'll continue to change my fluid often and based on that will offer the same to my clients, should they choose not to I'll be happy to sell them a transmission sooner rather then later.

Jonathan

Gilly · #9 12-16-2006, 10:18 PM

Quote:

So Gilly, what's the recomendation on trans fluid change after a rebuild?

There is no specific recommendation that I am aware of, interesting question though. I know they test-run the transmissions in the factory on a test rig, so makes me wonder if some of the initial wear of the discs, if that stuff is flushed away on that rig, then the new stuff doesn't get all the graphite stuff in it so fast. I don't really thing that particular type of graphite material will hurt (and probably would actually help) the bearings. On a factory reman I'd just fill and forget.

Quote:

I find it odd that once MB started to offer long term warranty's their cars went from requiring regular/routine/all encompassing service to needing essentially no service.

Yes, agreed. The whole filled for life idea is hard to get over. I know it will work if you are lucky,I just don't think the fluid change is going to change your luck, I personally know of a transmission (722.6)that was doing fine on the original fill of fluid at around 300,000 miles. I think this is abnormally high, but shows that it is possible to achieve high mileage on the filled for life concept.

Quote:

..I'm just carrying it through to another aspect of drive train.

Well, yeah a component that is in no way sealed like the transmission is. Take into account the fuel, combustion gases (blow by), ventilation air, etc and it's easy to see how the oil gets contaminated. What contaminates the transmission fluid is wear of the internal components of the transmission, and once the clearances are worn out of spec in the transmission, it's a slippery downhill slope. You can change the trans fluid and maybe extend the life of the trans, but if the clearances are out of spec the tranny won't be hanging around very long. If everything is working OK it'll be perfectly fine with the original fluid.
Gilly

jhodg5ck · #10 12-16-2006, 11:58 PM

My understanding in regards to transmission fluid is that a fluid change is in Large part to renew the components that not only lubricate but those which provide grip to the clutches. You can have brand new fluid in a transmission, take it out and get the trans temps up around 300 and that fluid will be shot, providing little protection and little to no aid to the clutches. It will smell cooked but it will look Great.

In chatting w/ the Tech's I know when transmissions come in that are Just starting to act up they often find just a fresh round of fluid will do the trick and the transmission will begin to function normally again and this is most often with the new full electronic .6/.7's.

My white 91 gets Driven when ever it does come out and by 10K I can notice a difference in how she shifts.. Swap out the fluid/filter and everything is back as it should be. The fluid never smells terribly bad and the colour is still quite red.

I still don't see why for the relatively small cost of fluid one would not want to give their transmission every possible chance @ a long life of dependable service.

Jonathan

ROGER E. · #11 12-22-2006, 02:42 AM

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I read with own two eyes at my dealer the revised trans fluid mandate from MB. They now say "to be changed at 39000 miles" and I can't imagine where that number came from. Why not 40K?

In any case I had it done at 45K miles but since the torque converter has no drain plug, you end up putting in four quarts. Or was it liters? The one and only tech who works on my C320 told me if I really wanted to get it all out, he could do a pressure flush @ $$$. I declined. I did notice that the shift quality improved after the semi-change.

Gilly · #12 12-22-2006, 06:15 AM

I'm checking again, just for you..........
Gilly

phouse · #13 12-28-2007, 03:21 PM

Why is the dipstick sooo special can't you just measure 53mm - 64mm from the bottom of a empty bicycle brake cable (the housing), warm up the trans then measure... Done deal..

BTW my 1998 E430 has the TC Drain plug

kchemers · #14 12-28-2007, 05:35 PM

I had a 1997 C230 I put 245000 miles on it and never touched the sealed for life trans, when I was rear ended and the car totaled the trans shifted as smooth as the day I bought it. My Mercedes dealer refused on a number of occasions to change the fluid. Also a number of mechanics I know say flushing the trans is the worst possible thing you can do, you are better off never changing the fluid

jhodg5ck · #15 12-28-2007, 11:02 PM

Quote:

Originally Posted by kchemers

I had a 1997 C230 I put 245000 miles on it and never touched the sealed for life trans, when I was rear ended and the car totaled the trans shifted as smooth as the day I bought it. My Mercedes dealer refused on a number of occasions to change the fluid. Also a number of mechanics I know say flushing the trans is the worst possible thing you can do, you are better off never changing the fluid

Funny, one of the best thing to happen to me profit wise was/is Mercedes refusal to change transmission fluid.. I get Lots of 90's cars that have never had their trans serviced and because of which are needing their transmissions replaced @ right about 100-140K mark.

Jonathan

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