I had the wheels rotated and rebalanced again today, which did not help 20-25 mph shudder problem.
I then brought the car to another Honda dealer who performed a "drivability test". They reported: "Did feel concern. Did check for codes (none present). Vech is going into econ mode at that speed (3 cylinders) and the feeling is the torque in between gears (at that speed) Condition is normal."
I question their conclusion because the vibration only occurs under load and I would not expect the econ mode to come on only in that narrow 20-25 range no matter where the car is in the gear range or rpms.
They also blame the torch "lock" or something? Wouldn't that occur at a set spot in the gear range and not at a set speed?
I ran further up hill tests after leaving the dealer and the vibration occurs between 20 and 25 mph in any gear: D, D3, 2, and even in first at very high rpms.
The gear box shifts smoothly back and forth through all gears when standing still.
I wonder if it could be an axle/linkage related problem from the over-tight tie down on the rail cars that the selling dealer said caused an original alignment problem.
Does the Dealer's explanation make sense?