I have read that replacing the vacumm control valve (vacumm modulator) is a good idea especially for transmissions more than 10 years old. It's a cheap item, and besides, the newer modulators come with an improved design that is supposed to work better with the vacumm.
My autotrans currently shifts hard, with hard jerks during upshifting. I had my modulator tested with a gauge and the pressure turns out fine. I will do an overhaul next year, but meanwhile, as a temporary measure, I will flush and replace the ATF and filter. I am also going to replace this modulator with a new one. My question is, is replacing the modulator worth the while?
1983 W126 (280SEL)