A thud when accelerating?

F150 DUDE

MEMBER
2008 FORD F-150
4.6L
V8
2WD
AUTOMATIC
60,000 MILES

I’ve noticed an intermittent noise that happens during acceleration. Basically, I’ll be accelerating from a stop light and keeping my foot on the gas and once I reach about 55-60 MPH, I’ll keep the speed there for a moment. Then, I’ll release the gas pedal to allow it to coast for a moment (let’s say to get ready to brake) and that’s when I’ll feel a “thud”. It’s when I release the gas pedal that it happens and typically in the 55 MPH range. It’s not all the time but it happens here and there. Any idea?

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

The "thud" you are experiencing when releasing the gas pedal in your 2008 Ford F-150 may be caused by a few different things. One possible cause is a problem with the drive shaft or u-joints. When you release the gas pedal, the drive shaft may suddenly slow down, causing it to bind and create a thud. Another possibility is a problem with the differential or axle. If the differential is worn or damaged, it could be causing the thud. Another possible cause of the thud could be an issue with the suspension. If the suspension components are worn or damaged, they may not be able to properly absorb the energy when you release the gas pedal, causing the thud.

I have seen the driveshaft yoke cause a thud because it will bind on the output shaft
of the transmission as the rear end shifts position, check out this video so you can see how to fix it:

https://youtu.be/p2snOCyqVMY

Can you please upload a short video of the noise so I can hear it?