87 300SDL Tranny Woes
 

To all,

I had this going on another thread, but I had it suggested to me by a sage forum member to start a new thread. Bottom line is that, last week I was driving to Costco and everything was fine. Coming back, the transmission refused to shift into 3rd or 4th gear. I was driving along I-270 at 40mph at 4000 RPM. Not good. Pulled over and checked the fluid. It was a little low and I topped it off, but no joy.
I spent a fair amount of time chasing down vacuum leaks and adjusting the bowden cable, to no avail. Based on advice in the other thread, I capped off the offending vacuum lines (to the EGR and air recirc valve), disconnected the kickdown switch to see if that was causing the problem, and finally put some Trans-X in it since it seemed I was heading to rebuild time. Minimal effect.
My questions -

1) Vacuum - When I hook the Mity-Vac up in the lines, the vacuum will go up to 15, but it goes up pretty slowly. Quite a bit slower than if I stick the 'T' right at the vacuum pump. Should the vacuum increase go fast up to 15 and the slowness indicate something else going on?
2) Do I need to unplug the kickback solenoid on the transmission to completely disengage the kickback circuit? I unplugged the switch under the foot pedal, but don't know if that's sufficient.

Any other ideas welcome since I haven't found the detailed tuning information on this transmission like we have for the 82 model. Thanks for any help!

- Ted