water in tranny- w124
 

HI. Could someone please explain how water/coolant moves, I presume through the tranny fluid coolant portion of the radiator, and contaminates the transmission fluid. How much water in the tranny fluid is necessary to begin to degrade the lubrication properties and cause problems? I guess the best way to monitor this risk is by regularly checking the coolant level in the overflow tank. Thanks.

If coolant is getting into the tranny, you've got bad news indeed. I doubt that the coolant can pass into the tranny fluid moving through the radiator. The tubes aren't even touching each other. What problem are you experiencing exactly?

Troy
1995 E420 92k

The tranny will not shift out of starting gear ( second gear-1988 300ce), although of course when I brought it into the shop this weekend, after driving 25 highway miles in second gear, it initially shifted for the tech!! Then, on his second drive, it wouldn't shift any more. Also, when it won't upshift forward it also seems to lose reverse. He is factory trained. He removed the tranny and yesterday called and told me he has found water in it, so I wanted to understand where the water comes from-I assumed it was via a defector radiator. Thanks.