Vibration when gas pedal is halfway down

I have a 1995 Honda Accord EX with about 240K miles; tires are in excellent shape. I’ve noticed that when I’m at highway speed, I get what feels like a vibration in the front wheels, like a slight shuddering. It goes away when the accelerator is fully depressed (adding significant power to the wheels) AND when the accelerator is not used at all (no power going to the wheels). But if the accelerator is halfway down, I get that continuous vibration. Where in the powertrain might the problem be? Has anyone had a similar problem and gotten it checked out?


I think that the first things to check would be the motor & transmission mounts and the joints on the front axles.