2015 Ford Mustang GT: Manual Transmission's Thud or Clunk Sound
March 23, 2015
I've noticed an odd aspect to our 2015 Ford Mustang GT's manual transmission. When shifting gears, there's often an accompanying "thud" or "clunk" like sound. This sound is not obvious, and I think it took me a few days of driving the Mustang before I picked up on it. But now that I know it's there, I notice it all the time. It bugs me, and I doubt it's "normal."
The situation is basically this: If I'm accelerating and upshifting normally in our Mustang, there is almost always a quick, physical-like "thud" right as I'm moving the gear lever into the next gear. This is with the clutch pushed in, obviously. It happens with the neutral-to-first shifter movement, and then the two-three and three-four upshifts. By fifth gear, it doesn't really happen.
If I've got the radio on or I'm really revving the engine during acceleration, I don't hear the sound. But even then sometimes I think I can "feel" it through the car. Sometimes it also seems like there is some related binding as I move the gear lever for upshifts.
Related to this, I've discovered a good way to replicate the issue. With the car at a stop, push in the clutch and move the lever from neutral to first. The "thud" will happen. But if you keep the clutch in, don't accelerate (the car is still stopped) and then move the gear lever around like you're upshifting, the lever's action is much smoother moving from gate to gate and there's no engagement "thud" sound whatsoever.
I've also learned that the sound doesn't happen if I slow down my shifts. If I pause while in neutral for an upshift, say a "one Mississippi" mental count, and then gently push the lever into the next gear, it's all good. But such slow shifting in a Mustang GT gets old.
Our car isn't the only one out there with this problem. I did locate this same issue on a sixth-generation Mustang forum. And apparently, the previous-generation Mustang had manual transmission issues as well. But it's something I hope we bring up with the service advisor next time our car goes to the dealer.
Brent Romans, Senior Automotive Editor @ 4,022 miles