Hello everyone,



Recently I took my 1985 Mercedes 300D on a 40-mile drive on the freeway. I've owned the car for about a year and a half now, and everything was working great. The transmission shifted as it should, engine ran very well, etc. I got home, parked it and then started it up again 3 hours later because I had something else to do. When I got on the road, the transmission would not shift into 2nd and kept revving. Confused and annoyed, I pulled back into my driveway to investigate. That was three days ago.



Since then, I tested many things to see if I could find an issue, but still nothing. I'll go ahead and list them below for reference. The car has 223k miles on it with a 722.315 transmisson.



1. Checked fluid level; a little high, so I used a vacuum hand pump to get the excess removed. No change.



1. Checked Vacuum; 25 inches of Hg at idle from direct pump line. 18 from VCV when at idle and bleeds off to ~13 when accelerator is pressed. (Checks out, no issue found.)



2. Checked Vacuum modulator; holds vacuum as it should. (Yes, I used a different mityvac from the one used to drain the atf)



3. Unplugged kickdown switch and made sure it wasn't stuck.



4. Dropped transmission pan to look for debris. Pan was clean as can be, but I changed the filter and fluid anyway. Added trans-x both before and after I dropped the pan.



5. Checked the tightness and adjustment of the bowden cable. Cable has tension when pulled (while disconnected from the throttle, proving it hasn't fallen apart.) Cable was re-adjusted too. This caused no change.



I was also able to get all my gears back if I revved the engine high enough, but the transmission only shifts at 3.4 k rpms now, while it was shifting at around 2.0 k rpms before.



Please help... I'm completely stumped. Feel free to ask questions, as I will be happy to answer them.