My '83 300d turbo had a bad vac modulator, that I replaced. The trans shifts from 1-2 with the lift of my foot , then when in 2nd it will suddenly jump out of gear or slip. I'll let off the throttle and it will go back into 2nd . After a little acceleration it will slip or jump out of gear again. Once it gets into 3rd then 4th it seems ok. Would a superior spring kit help this problem or is 2nd gear going?

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