I'll add my Vacuum Modulator experience. I purchased my '93 190E 2.3 new and it always shifted hard from first to second gear. I replaced the VM when the VM started leaking transmission fluid through the vacuum line. The transmission never shifted better and so smooth... it still does.
To replace the VM, I had to disconnect the exhaust system hangers so I could lower the transmission enough to gain access to the VM bolts.
Also, this would be a good time to replace the shifter bushings while the transmission is lowered.
