300cd trans problem

[BenzTurbo]

the trans in my 1983 300cd has been acting up for a while. when the car is cold it "flares" in the 2-3 and 3-4 shift. 2-3 always seems worse and the 2-1 downshift is hard. once everything is up to temp the flaring goes away unless you're very easy on the throttle. when you accelerate hard, there is no flaring. My vacuum system does not have any egr crap and i have tried both disconnecting the vacuum to my trans (hoping for all shifts to be very firm) and swapping my vcv calve for a known- working one and no luck... with no vac, 2-3 and 3-4 still flare but once the gear "grabs", it is harsh. I have turned up the adjustment key on my trans modulator and it seemed to help a bit. when i really get on it, i get second gear rubber lol . is my modulator bad? do i need those spring kits i have heard about? i don't think my trans is bad because once it is in gear it does not slip at all. thank you!