PeachParts Mercedes-Benz Forum - View Single Post - 1994 E320 - transmission slips when starting off in 1st

Wayfarer · #1 06-05-2012, 01:19 PM

Searching through the archives, tells me that my symptoms are not all that common. So here goes...

1994 E320 with 109K miles, new to me a few months ago. From all accounts very well serviced, proper stickers, including a recent service sticker on the transmission itself. Just to be absolutely safe and to start with a known baseline, I had the transmission fully serviced by my trusted indie, full drain including TC, new filter, the works. Afterwards I noticed that the transmission seemed to occasionally slip for a moment then engage when starting from a complete stop, especially when cold and/or after shifting to D from reverse. It slips for just a moment, maybe a half second...not even enough time for the motor to rev...then gently clunks into gear and off I go. Only happens when I shift from R to D or when I roll a stop sign. All other shifts 2-3, 3-4 are normal. It semes to not do it much when car is totally warmed up, although it ocassionaly still does. It is most pronounced when cold in the morning, always doing it after I back out of my driveway and shift from R to D first thing in the morning on my way to work.

After driving it like this for a week or so after the transmission service, I checked the fluid level and found that it was waaay over the full mark. Thinking I had found the culprit, I drained a full liter before it came back down to within the marks. Yes, I measured it fully hot, in park, idling, etc.. Now the fluid level is right on the money. However, the problem persists, and if anything it is even a little worse now that the fluid level is at the correct level.

The clunks are not at all violent but clearly perceptible and somewhat disconcerting...I know I am not doing the driveline or transmission any favors by driving it like this...although not being too bad, I could probably drive it like this for a long time before anything real bad happens. It doesn't happen all the time, but is intermittent, except when cold when it does it pretty much all the time. I drove the car about a month (1,000 miles) before the tranny service and did not notice this problem until had the transmission serviced. Otherwise it shifts perfectly. 2-3, 3-4 are crisp, perfect really, and it goes right into reverse with practically no delay. Reverse works great, no issues there. When I bought the car, I thoroughly tested the transmission and it worked perfectly then. This is my 5th W124 and I did not want to deal with transmission issues yet again, so I was very careful this time making sure the transmission was good...I digress...

Any ideas what is going on? My only thoughts are that something (dirt) got plugged up in the valve body during the recent transmission service. I don't think the overfill would have caused a seal to blow or other damage. When it was overfilled, it did not foam or overflow out of the transmission. Or maybe clean fluid dislodged something or otherwise altered the function of the transmission?

Is there any point to pulling the pan and say checking/replacing the B2 piston and or dropping the valve body and thoroughly cleaning it? Perhaps incrementally adding in fluid to see if there is a sweet spot it likes a little above the max mark?

Love this car. First M104 after already enjoying the M103 and M119. I did not know what I was missing. The late M104 E320's really are a joy compared to the early 300E's (another great car by any measure). The transmission is much better on these cars (save for my minor issue discussed here).

Thanks.

Darren