I have a 1993, 944T with an automatic transmission. Engine coolant was leaking into the transmission fluid and vise versa. The radiator was replaced and the transmission fluid and engine coolant were replaced. That was in the summer.
In the cold weather, i.e. below freezing, the transmission resists shifting out of first gear. It also difficult to shift from second to third, etc. Also, the kick-down cable sticks; it "freezes" so that the throttle cannot be opened and when freed, it stays "open". When the engine warms up, shifts become normal again. However, even at warm temperatures, upshifts often require backing off the throttle
My suspicions are that there is residual water-based fluid/gunk in the transmission that freezes when cold. This would prevent normal operations especially when cold.
Do you think that I am on the right track? Any suggestions as to the cause?

Regards,
and Thanks.