Tranny issue....maybe

I have a 97 Buick Regal GS with 109.000 miles. She really is a great driver still. Twice so far when I drive away first in the morning (cool/cold) I get a shudder.. i think. It feels like a warped rotor (with brakes on) transmitted thru the steering wheel. But when the car is warmed up after about 3-5 miles it goes away. No CEL . I've owned the car since 64.000 mile and have never chenged the filter or tranny fluid. Could it need a change or would I be opening up a 50 gallon bucket of worms ?

Do the basic tranny service. ATF - Dextron-III and screen filter first. Also, you could add some Lubegard additive (8 oz). Shudder is a sign the PCS solenoid is acting up because there is a line pressure problem.