When I shift my Lincoln Towncar into Drive and drive down the street I feel a gentle thud/hesitation (very brief loss of power) at approx 30 mph. Is this just something I need to become accustomed to? I never experienced it before (on mostly FWD vehicles).
One must assume this vehicle is new to you. What year is it?
Try the same drive with overdrive turned off.
30 MPH is a little slow for overdrive to be engaging, although it does sound like he’s describing the 2-3 upshift.
Try leaving the transmission selector in “2”, then drive the car up to 30 or 40 mph. I’m guessing that you won’t feel your “thud” or “loss of power”.
(Apparently) You’d be amazed at how quickly these V8 cars will shift into overdrive, if being driven gently. Also, you do know that these are now 4 speed transmissions plus overdrive. I stand by the thought that it is the shift to overdrive that he is feeling.
I have a Crown Vic which uses the same transmission. I routinely lock out the overdrive when driving in urban conditions. The lock-out button is on the end of the shift stalk…This saves a lot of needless shifting and wear and tear on the transmission…
Most overdrives run the engine at 1800 to 2000 RPM (or so) at 60 mph. Therefore, at 30 mph the engine would be running at 900 to 1000 RPM. So, yes, I would be amazed if the the transmission was shifting into overdrive at this low a speed. As for being driven gently: if it were, I suppose the OP wouldn’t be feeling his “thud” and loss of power.
But, if the transmission does shift this early, I stand corrected.
Mine stays in overdrive down to 800 RPM.
My Lincoln LS shifts into overdrive at 28 MPH.
The 2-3 shift on my 1993 Caprice is around 30 mph during gentle acceleration. Compared to my other cars, the shifts are firmer, but not abrupt. I don’t notice any loss of power though. Depending on the year, there may be a cable adjustment for the shift points on your car.
When the Caprice started hanging up in first gear and then slamming into second, a small adjustment (1/16" - 1/8") of the TV cable fixed it. I believe for newer cars, shift points are controlled by the car’s computer.
The transmissions are 4 speed including the overdrive unless you are counting the TC lock up as a “gear”. That would be incorrect since there is no ratio change.