Trans "surging" when cold.
 

300SDL

When cold the trans seems to surge in/out of neutral and even feels a touch slippery. I recently replaced the modulator (which eliminated the significant 2-3 & 3-4 flare) and cranked up the pressure a little and that seems to have really helped the slippery feeling in the morning going up the hill in front of my house. I have it adjusted up to where the 1-2 shift is pretty firm and the rest of them are adequate. The surging and slight slip when stone cold is somewhat alarming.

Once warm it seems to be just fine. Whats up with the surging? It did that even before the modulator replacement. Ideas welcome.

Tony