My 2006 LTD Roadster, 6 speed manual, runs at half the gauge, but can cycle a bit. This, I feel is a function of the thermostat and the temp fan relay. They do have a dead band in which they operate. As far as the trans is concerned, mine is a 6 speed manual and I have only driven an automatic once. It sounds like something is not correct if you feel it engage, disengage, etc as you drive.