i have an 86 300E with about 175,000 miles in it. i just got done putting a refurbished head on, deck cut, valves and guides. got the old girl running and all topped off and set to go. the tranny wont up-shift even at 5500 rs. checked out the switches and linkages and didn't find much off there. disconnected the tans pressure cable and no diff. run Through all the vacuum lines and connections and didn't find any leaks. pulled the hose off the vacuum. modulator unit and no ATF so that's at least not leaking. tried to go through all the arcane linkage adjustments. talk about week info out there BTW watch the Cd's out there for the 124s. mine has an incorrect wiring order in it!! it's original MB and got it on ebay.
anyway, not too familiar with the Benz as this is my first. any of you Benz guys out there have some help for me?? is the modulator stuck? something else? did i miss the linkage setup setup? would love the help jim

Disconnect the kick down switch wires under the gas pedal, or no governor pressure, with the rear wheel off the ground, remove the governor cover, drives side rear of transmission, turn the drive shaft or wheels and verify the governor turns. Too check governor pressure you need a low reading gauge, 0 psi to 50psi

so where is the pressure check port?? and thnx by the way. also, pulling 17" of merc on the vacuum gauge. is there a work around for this problem?? just so i can get it from place to place? it seems the critter wants to think it's gettin kicked down all the time so wont upshift. is there a good book onthis trans? i've rebuilt a few GM transes b4 so i'm cool with rippin this 1 out and down for a R|B. but where can i get a R|B kit? she has developed a few leaks sitting for the last year and i hate leaks!!! also are there any upgrades or updates i should be doing to this gal?? thnx and i'll be checkin this out right now. jim

Driver’s side front of the transmission, the two wires under the gas pedal activates the KD solenoid, disconnects the wires front the switch.

spent a bunch of time hunting for info, like a road map to where everything is and suck. printed off an almost complete book of the trahs from eAutoRepair.net@mitckell1.com. full tear down and R|B plus some decent diagnostic steps. has all the rest of the stuff as well. it did cost like $8 to sign on to use it for a week but i think it's worth it thnx for you input folks and when i get if figured out i'll post what it was and what it took to fix. also went hunting for worst case parts and found a few places that sell trany parts on the web including a full R|B kit with friction disc but not the steels. importecparts.com & buyautoparts.com where both under $200 for the kits from Precision International plus a vac modulator or what ever MB calls it at $40.
aPS. any tips on stting the cranck sensor without rippping half the top of the engine off? i marked it b4 teardown but not well enough i guess so it may be off a bit thnx all. jim