Transmission fluid replacement schedule - Page 2 - PeachParts Mercedes-Benz Forum

jhodg5ck · #16 12-15-2006, 09:07 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 · #17 12-15-2006, 09:41 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 · #18 12-15-2006, 10:23 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 · #19 12-15-2006, 10:36 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 · #20 12-15-2006, 10:41 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.

waybomb · #21 12-15-2006, 11:02 PM

Gilly, I respect what you are saying, but, mine was black, burnt, and at least 15 needle bearings in the pan. The fluid clearly had metal in it. There was no magnet in the pan. Maybe the bearing that failed, and resultant damage, was all a result of an early Monday morning or late Friday afternoon bearing.

Maybe changing it at 30 k or 60 k would not have saved this tranny. But if it did, we would never know, now would we?

Gilly · #22 12-15-2006, 11:09 PM

No, we wouldn't, true that. We can agree to disagree, n/p.
Black is one thing, burnt is another. We were told this fluid will be quite the same as an earlier transmission, that the "sniff" test is a valid one. I think you'd have some symptoms prior to the fluid getting to this point (burnt) though, ie clutches slipping and you'd be aware that something un-good is occuring in your trans. The black appearnce means nothing, this is a tranny, not an engine. On an engine, specifically a gas engine, yeah you normally don't associate black engine oil with a well cared-for unit.
Gilly

Hatterasguy · #23 12-15-2006, 11:48 PM

Gilly I was under the impression MB is now recomending a change at about 30k miles, then filled for life after that?

Anyway it isn't that expensive, every 50k-60k miles can't hurt.

Gilly · #24 12-15-2006, 11:53 PM

Just checked with the old boss, nope, no change to the recommendation. Again the dealers may pull something to make people think MB changed it, but MB still maintains they are filled for life.
Gilly

Hatterasguy · #25 12-15-2006, 11:56 PM

Hmm interesting.

Our dealer does recomend it, they don't push it but if you ask they are more then happy to do it. All the service guys seem to think its a good idea, wonder why...

Gilly · #26 12-15-2006, 11:59 PM

Quote:

All the service guys seem to think its a good idea, wonder why...

Because they can sell you a tranny service. Then on the slim chance the tranny lunches itself (which it'll do if it damn well feels like it anyways), then they can ALSO sell and install a reman tranny for you. They miss doing those tranny services like they did in the olden days.
Gilly

waybomb · #27 12-16-2006, 05:17 PM

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

jhodg5ck · #28 12-16-2006, 05:43 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 · #29 12-16-2006, 09:18 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 · #30 12-16-2006, 10:58 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