While having the injection harness replaced on my 300se(1992) by a local repair shop, I decided to get a general service. Included was a transmission fluid change and I asked'm to look for something rubbing against the drive shaft. In reverse I was hearing what I thought, was a rubbing or gear like sound. Yesterday I got the car back. After driving about an hour I got to a place where I had to back-up and NO REVERSE! It felt like it was trying to go backwards and I'm not sure if it rolled or had a little help from the tranny but I got the car home and parked it. Forward shifting seems fine. I checked the fluid but can't seem to get a good reading...franky never have...it either looks way past full or too low...Is there a trick that I'm missing to get an accurate reading on how much fluid is in the tranny? The fluid that came out of the car doesn't smell bad and was the correct color. I did notice that dip stick and filler tube seemed to be abnormally hot. Is it possible that there is simply not enough fluid in the tranny or was that noise a prelude to having some major tranny work. I'm bumming out that harness bull set me back a "G".