Car shudders when accelerating in 5th

[Nikki]

I've noticed that when I accelerate on the interstate, sometimes the car will shudder quite badly. Its very similar to the way the car behaves if you overshift early, except I am well into the speed range for 5th gear. The vibrations stop as soon as I release the throttle. Also it seems to occur more often when the car is traveling up a slope. All other gears accelerate smoothly with no problem. I have also noticed that when the car is moving in 5th gear, I can hear a faint whistling noise-I'm not sure if that is related or not.

Any help would be appreciated!

[benemorius]

Yeah, I've had that problem before. My prefered solution: downshift.

heh

Kidding.

Seriously- what speed are you going, and at what speed does it stop shaking?

[Nikki]

I told yeh it wasn't a driver problem!

Usually it starts roughly at 65 MPH-and only when I am giving the car throttle.