Transmission Fluid Leaking

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Justintyme

Active Member
Joined
Feb 3, 2018
Messages
997
Location
Ireland
Car
Mercedes Benz w212 E Class
Some months ago ( 5/6) the fluid, filter and electrical socket were all replaced by my local Indy. Since then, no problem, But this morning I had to reverse with a loaded trailer (300-400 Kg) on to the lawn. The box seemed to be revving up a bit more than normal, but I put that down to the rear wheels slipping on the wet grass. I disconnected the trailer, and again as I drove off the grass, another bit of slipping, which seemed to stop when I reached the concrete yard. So I drove into town and back out again....20 Klms, and as I drove back into my driveway..I saw a thin line of transmission fluid on the surface. I looked underneath, and there is a drip / drop of trans fluid, straight down from the under shields at the bell housing. Any idea's anyone? I'm taking it into the workshop this evening to put it on the life and try to see what is the cause. But any suggestions of the possible cause would be more than welcome...and also possible costs...
Thanks
 
I would check your power steering hoses as well. When they spring a leak it looks just like you describe.
 
I would check your power steering hoses as well. When they spring a leak it looks just like you describe.
Good Idea, ManofKent. I'll check the power steering reservoir as well. It's booked on to the lift tomorrow @14:00 Hrs. So I will get some idea of where the leak actually is....at the moment, it's dropping off the underside splash trays directly at the bell housing, so hard to tell exactly where it is leaking... but definitely red fluid. Could also be from the oil cooler pipes either to or from the oil cooler, or indeed from the cooler itself. Hard to tell at this point. The oil cooler pipes would not be such a big job, or indeed the cooler ( I think) but the thoughts of the trans having to be removed and stripped down,,,that could develop into a major horror story. But looking at the bright side ( your side...:D:D:D) I'm optimistic !!!!:rolleyes::rolleyes::rolleyes:
 
I think...that there are seals at the front of the box that can be replaced without much more than removing the torque converter. Box has to come out (obviously) but no need to break into the box.
As you intend to do anyway, check the (easier dealt with) peripherals first.
 
I think...that there are seals at the front of the box that can be replaced without much more than removing the torque converter. Box has to come out (obviously) but no need to break into the box.
As you intend to do anyway, check the (easier dealt with) peripherals first.

Thanks for your help Bellow. When I first saw the leak, directly under the bell housing, my first thought was of manual gearboxes I worked on many years ago...and the crankshaft seal. Either that or the opposite one in the gearbox housing. So if it is only that seal, it's not so bad....I certainly hope so !!! Is it a big job to remove the 722.6 Transmission, replace the seal (s) and refit the trans in the w212 Merc?
 
Thanks for your help Bellow. When I first saw the leak, directly under the bell housing, my first thought was of manual gearboxes I worked on many years ago...and the crankshaft seal. Either that or the opposite one in the gearbox housing. So if it is only that seal, it's not so bad....I certainly hope so !!! Is it a big job to remove the 722.6 Transmission, replace the seal (s) and refit the trans in the w212 Merc?

I'm not entirely sure that a front seal is so easily accessible on a 722.6, I'm thinking of older American autoboxes which were simpler. Try and find an exploded diagram/parts list to see method of assembly. If it is that, it'll be a lot simpler than having to strip the box. But check peripherals first. Removing and refitting the box is something any garage should be able to estimate time for and therefore quote a price. Some though, may be reticent to go into the box - even for a simple seal change. Are there any online videos of working on 722.6 boxes? If so, what you need will be covered early on.
 
Update on leaking 722.6 Transmission.
So after spending a night tossing and turning, and crazy dreams of red fluid splattered all over the room,crazy gears meshing in agony,,,I managed to get the car up on the lift in my local Indy's and removed the under shield's. Plenty of fluid visible, all over the sump and adjacent areas, with a small pool still remaining in the hollow formed in the shield. And the culprit turned out to be? The electric socket for the conductor plate. Despite the fact that it had been replaced less than 5'000 Miles ago. This is what threw me.. I was not expecting it to be the source of the leaking fluid. And my mind was running riot with the possible alternatives. Anyway, I am quite relieved that it was only the electrical socket ( and nothing more serious ) but a bit dissapointed in a part that only lasted 5'000 Miles. And so the postmortem...to recap: I was reversing a trailer onto a level grassy area ( Trailer loaded with 500 Kg approx ) The grass was still wet / damp from the dew, and the rear wheels were slipping a bit, with a bit of extra revving needed to move the trailer into position. After unhooking the trailer, short drive into town and back home again ( 3 miles max) Turning into my driveway, I noticed the straight line of leaked trans fluid. And that's where the story began. So by way of explanation, would the revving and slipping with the trailer on the grass, have whipped the fluid into a frenzy, and forced it out via the electrical connector? Overnight, when parked it did not leak a drop. And neither did it leak under normal driving today...Lead's me to suspect that what ever was forced out of the box, lay in the under shields until it was splashed out, but that no more fluid was leaked out. Is this scenario feasible? All thoughts comment's etc are welcome.
Justin
 

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