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R129 SL500 (98,97,95,92), W124 (E500&320 93Cabriolet)R107,Toyota Landcruiser2010, Nissan Murano2015,
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Discussion Starter #1 (Edited)
Hi all,

As shown in my signature I have SL600 1995 which required a new Throttle Body Actuator driver side, however after long time searching and searching I have managed to find a used one in good condition, the car is running good now.

The car was parked for six month and when I tried to drive it for a short distance I have noticed the gear shifting is extremely rough especially from 2nd to 3rd gear, thought it might be a shortage in the transmission oil, I checked the oil level but here is the shock! The oil colour is beige and the viscosity is 0, and same case for the coolant!!!

Called my garage guy and asked him why it happened even if I don’t drive the car?
He told me the whole problem is from the radiator since it has two parts upper one for the coolant (engine) and lower part for the transmission.
It can be solved there is no problem, all what I need to do is replace the radiator and transmission filter and flash the transmission. Of course add new oil and coolant.

My question is: how did that happened and what is the reason?:confused:


Regards,
Omar
 

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95 SL500, K&N, NEOKEN Ported TB, Custom Intake, RENNtech Sport Exhaust, AMG I Monoblocks
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My question is: how did that happened and what is the reason?:confused:
Hi Omar, the reason there is engine coolant mixing with the automatic transmission fluid is more than likely due to a transmnission oil cooler failure.

Please take a look at M120 engine coolant & transmission fluid mix for a more detailed explaination of how this could happen.
 

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R129 SL500 (98,97,95,92), W124 (E500&320 93Cabriolet)R107,Toyota Landcruiser2010, Nissan Murano2015,
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Discussion Starter #3
Thanks NEOKEN for the link,

Any Idea how i can avoid such issue if the future, replacing the radiator is very costly!!!
 

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MB SL600, MB 380SE, Suzuki Grand Vitara, 38' Chris-Craft, Volvo V70XC, and my own two feet...
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Thanks NEOKEN for the link,

Any Idea how i can avoid such issue if the future, replacing the radiator is very costly!!!
The rad really isn't that bad, iirc I paid <$500 for oem.

And if it's shot it's shot, you gotta replace it. DO NOT DRIVE THE CAR in the meantime.
 

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R129 SL500 (98,97,95,92), W124 (E500&320 93Cabriolet)R107,Toyota Landcruiser2010, Nissan Murano2015,
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Discussion Starter #5 (Edited)
The car is in the parking since long time, I was starting the engine once in a while before I discovered the radiator problem, I just started and drove it for 20m to make sure the Throttle Actuator is working.
Planing to take it to the garage within the next two weeks since I cannot do it my self at home.
 

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wow that is awful! I never heard of that actually happening. To me it seems you would want to find a creative way to clean the trans without ruining it after you fixed the radiator/trans cooler.
I would be suprised if it were even safe to turn the trans at all until it was thoroughly cleaned. Is there a cleaning method someone has figured? Im thinking something like filling it way overfull with *anhydrous Isopropyl alchohol or chemically PURE glycol (no water) a few times followed by kerosene a few times and then with new trans fluid several times, then run it a bit and change it again and then again.
* I would be afraid anhydrous methanol or ethanol could hurt rubber seals.

Those are just my immediate thoughts and someone may already have a cleaning procedure. I would even probably come up with something better myself every hour I thought about it. Maybe just purging with new fluid a few times would be good enough, I dont know. The torque converter will need drained and cleaned too.
Even residual traces of water seems not good , in my opinion, but extremely small amounts of water would evaporate from a transmission by driving if the transmission did not fail beforehand. Residual water would evapoarate from "hot" transmission fluid. I dont know how well it would work to just change the fluid a couple times and then somehow heat the trans for a while without running it. I dont know how hot is safe for a trans but I think 120C would be OK and that should drive off residual water.
 

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R129 SL500 (98,97,95,92), W124 (E500&320 93Cabriolet)R107,Toyota Landcruiser2010, Nissan Murano2015,
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Discussion Starter #7
Hi Alchemy,

Many thanks for your thoughts and suggestion, according to my local garage the best solution to flash the transmission and clean it up is to spray the whole transmission with petrol (gasoline) and of course replace the Filter,if I refill the transmission with some special liquid and drain it couple of times I will end up with replacing the trany filter couple of times.
I think will leave it to my garage to do it, it seems it is a common and had experienced the problem before
 

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another possible way I thought of to clean is if it would be OK to fill the whole case with kerosene run the trans on the rack for a bit and then leaving it sit a day or 2 , remove the pan and all water should be in the pan since it goes to the bottom. That would remove the vast majority of water. I dont know if you could run your trans with only kerosene. Water may separate to the bottom in ATF eventually also if allowed to sit long enough.
 

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Discussion Starter #9
That will be a good idea, but I still prefer to flush the engine with gasoline since it will take shorter time and less hassle!
Will contact my garage on Sat and check with him what is my options.
 

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coolant and trans oil mixing

if the car has been driven with the coolant in the trans then it will have to be removed and overhauled including the converter. there is no way to get the coolant out of the trans and it will destroy the friction materials in the trans and the water will trap itself in the bearings. you could then install a new radiator or have a seperate cooler installed for the transmission but make sure it is a good qaulity cooler such as a true cool. if you just flush it it will act up everytime it get's hot and it will eventually fail.
 

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if the car has been driven with the coolant in the trans then it will have to be removed and overhauled including the converter. there is no way to get the coolant out of the trans and it will destroy the friction materials in the trans and the water will trap itself in the bearings. you could then install a new radiator or have a seperate cooler installed for the transmission but make sure it is a good qaulity cooler such as a true cool. if you just flush it it will act up everytime it get's hot and it will eventually fail.
I can picture that extreme as a possible but not an absolute. I think the hardest part of "rebuilding" a trans in one of these is removing it from the car so I dont see the point of not trying to clean it without removing it from the car. If it is as extreme as you say and too many "channels" will retain coolant then I still say something like filling the case with water miscible solvent such as anhydrous isopropyl alcohol or pure 100% ethlyene glycol followed by hydrocarbon or ATF washes could easily work. A typical mechanic may not think of things like that although a mechanic experienced with a cleaning method may have a "non chemistry" type procedure. As for what he mentioned, if it was done a few times, it may work also because the coolant will stay emulsified with the ATF long enough to drain it out or reach the pan no matter where it is. There may be residual, I would guess 1% or less after any thorough "washing" but that should boil/evaporrate off quickly.
If it works he saved a bundle, if not, he lost the time and cost of cleaning it.
 

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oil/coolant mix

thank you for the reply. The clutch plates are made of fibre that are bonded(glued) to steel plates. One of the plate manufacturers tests revealed that two table spoons of water when turned to steam diplaces two litres of trans fluid, not to mention what the chemical reaction does to the bonding of the friction plates and bands. I've tried several times to flush coolant out of transmissions for customers but it's a waste of money, but of course people will still try doing it. Best of luck.

Doug
 

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just got through typing a lengthy reply and poof "web page cannot be displayed" and its gone.
Generally I explained azeotropes which is what it sounds they were referring to and how I felt it would normally be the other way around with something like 90% water and 10% ATF.
More importantly, your experience is very valuable and it would be of benefit to know how you did it that doesnt work so he would know to try something else if possible. Also they make it sound like the clutch binders are water based. I admit I was considering all possible materials in the trans when I was "chosing solvents" but I only thought of rubbers and plastics. Do you have more on what the adhesive is or anything else beside plastics or rubbers?
 

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trans fluid/coolant

Raybestos Powertrain sorry i don't know how to properly install a link with my mac but this is the page made by one of the clutch manufacturers about water and transmissions. Just a note that the guy drove the car and noticed that the shifts were rough before he noticed the water contamination.

Doug
 

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Ok its not talking about "water boiling off 2 quarts ATF per oz water" that I assumed they meant. What they mean is the pressure produced at 100C when the water boils could cause ATF to blow out somewhere because of the pressure. Minute residual water after a good cleaning of some sort probably would not cause a problem like that but if that were a concern then running it below 100C for a while would prevent that possibility. Water will vaporize and leave at 90C but not nearly as quick as at the 100C BP . I admit that is a very good consideration with larger amounts of water especially in the TC or somewhere where hot ATF may be confined away from the vent for some period of time. TCs can reach 400 psi or so, I think, and water would have to get some crazy high temp before it would boil at that pressure. Even as high as 205C, 401F, the pressure is only 235 PSI. What it may do is "flash" boil when it left the TC to the trans and possibly blow ATF out of the filler tube or the vent. That is probably what they are talking about. On a MB trans it has a vent much lower than the dip tube and would come out there first, I assume. It seems wide open but maybe someone who has acrually taken one of these vents off knows more.
I disagree with their concern for very small amounts of water staying put for long periods like the hygroscopic nature of the discs assuming they mean even if the trans is being used. That would evaporate off above 100C and never return even if it was water from "hydration" (from a hygroscopic material). On the clutch adhesive they are talking about absorbsion of water on the disc and eventually though the adhesive, rusting the steel and causing the adhesive to break loose. This would not be immediate. They start out by the typical scenario where a person does not notice water in the ATF for a while.
They do not rule out that they could be cleaned sucessfully. They do say they are quickly on the road to needing rebuilt with water in them and I agree. Length of time with water contact is critical. Their article also made me realize a trans sitting a long time could absorb enough water from humidity to really hurt stuff. I wonder if anyone had considered using a dessicant cartridge on the vent?
Thanks for that link. Some good thinking on there.
 

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I wonder how it would work to put vacuum on the trans? Or to adjust the vacuum to whatever would not damage something, if it could. I forget what it is exactly but Ive seen water boil out of a vessel very quickly at room temperature at something like 10mm or 28", I forget. All of my vacuum pumps will boil water off at room temperature. Vacuum is a standard way of drying things in labs and plants. Most vacuum pumps used by refrigeration service will easily boil off water at room temp. Even if one felt safe at only 20" of vacuum, that would still vaporize and remove water, especially if it were warmed a little. A person could also monitor its progress and when it was dry by running the outlet tube from the pump into a cooled container to see when the condensate stops.

I guess the main seals would be the limiting factor and there maybe other weak points I'm not thinking of. The dip tube and vent would need stoppered. I think it would safely take 20" vacuum. 20" vacuum and heating the trans with a heater to maybe 50-80C for about 24 hours seems like it should remove all water.
 
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