Crazy Tranny

[Darrell Woods]

Been driving a '97 E320 for the past three years. As soon as the outside temp drops to approx 40-45 degrees, the tranny 1.) slips and 2.) will not upshift out of first. Posted initially a couple of years ago and someone said it could be some type of spring that's internal. MB dealer said, drumroll here, replace the transmission. I've done nothing because...if I shift it to "4" rather than "D" it works great. After a mile or so, I flick it over to "D" and I have no more issues until it sits and gets completely cold again. I have noticed when it's really cold that it slips in "R" also. I have no idea what's going on internally with Drive versus "4". Why would one work perfectly, and the other be a dog in the cold? Does it really need a new tranny, or is it something a little less costly? Actually went to two MB dealers, and both said replace based on nothing more than a test drive after the car sat out in the cold overnight. Two independent shops spent some time looking into the problem, but both stated MB has proprietary equipment that keeps them from really troubleshooting this electronic tranny? Any thoughts? Thanks.