weird shifting problem 86' 300E 4dr sedan
 

Last month my 1986 300E would spontanesously down shift into 3rd, 2nd, 1st, and even neutral as I'm driving on the freeway at 50-60 mph.

I was told that it may be the Automatic transmission Filter, so I changed it (and the transmission fluid). The problem went away for a few weeks, but now it's back. Although this time I notice that the problem only occurs when the car has been driven around and the engine/tranny is warmed up. If I drive the car in the morning and let it cool off for a few hours then return home everything is fine. But if I'm driving the car around the whole day, the shifting problem occurs.

Note: The fluid levels are fine, and it doesn't smell burnt. The car ran fine until the transmission began to "act up". The car has 150,00 miles on it.

Any advice would be appreciated.

jrmd01@yahoo.com

If your trans fluid hasn't been replaced in awhile, upon fresh fluid, it is said that old "gunk" can be loosened up in crevices, etc. Therefore, it is recommended to flush the trans AGAIN after a short time.
Worth a try if you're up against replacement of the transmission. 150k miles isn't that many for a MB transmission.... unless the fluid was never changed.

GOOD LUCK!

I agree with David. My 300E sedan had the same symptoms. A follow-up fluid change did the trick and the transmission was again as smooth as ever.

UPDATE on transmission 86 300E
 

Thanks to everyone who replied.

I re-flushed the transmission and replaced the filter and gasket. I drained ALL of the fluid (from the pan and torque converter). There was a total of 5qt drained. (This may have been the problem afterall because I was checking my fluid with the engine cold...duh)

Anyway after replacing and draining everything. I put in 7qt of Dexron III fluid and it seems to run fine. I checked the fluid levels after driving the car around for 20min or so and it's between the 2 marks.

I hope the problem has been "cured", otherwise I think I'm going to have to rebuild or replace the transmission.

There was something that bothered me though when I bought the gasket for my 86' 300E, the sales person told me that my gasket was actually listed under the 190's. What was that all about? My gasket sort of looks like a figure "8" the "other" 300E gasket kind of tapers off. Did MB use the 190 transmission in the 1986 300E?

I spent $40 hoping to save $2000. I'll find out for sure this week if the shifting problem is gone.

Again, thanks to everyone for their advice.

jrmd01