[V8] cold weather problem /thermostat

[jidodd at shaw.ca]

Hi
In my first message I said the car is buckling.Meant to say bucking.
Just another thought I had after seeing a post.Could it be that the solenoid in the tranny pan is not working and then my torque converter
is causing all this ?
BTW I did change the regulator and O2 sensor not long ago.

2.I also noticed my temp gauge never goes above 55 C in this cold weather.
Should I suspect a thermostat problem ?
Is the procedure simple for that job ?
thanks
John