Random clunk?

HELPNICKPLEASE

MEMBER
2020 FORD F-150
4WD
AUTOMATIC
17,000 MILES

Every now and again I’ll hear a clunk or a knock. Just one. Usually after I hit the gas after a complete stop. No engine light. If I bounce the front or back I cannot make the same sound. It doesn’t happen when I go over bumps. I did have to have the gas tank replaced in spring due to vandalism, but noticed no faults until now. Regularly serviced. Oil life is currently fine.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

Can you tell if the sound comes from the front or rear of the vehicle? I ask because if it is in the front, it could be a failing engine or transmission mount. If it is in the rear, my first suspect would be a universal joint.

See if you can notice an approximate location. If it is the front, I need you to check something. Place the parking brake on, open the hood, and start the engine. Have a helper place the vehicle in drive while holding tight on the brake. Then, gently apply a small amount of throttle to the engine. Pay attention if the engine seems to lift on one side. A small amount is normal, but if it is more than an inch, then there is a good chance the mount needs to be replaced.

Also, here is a link that explains how to test a universal joint. Note: Often times when a universal joint fails, you will feel a vibration while driving.

https://www.2carpros.com/articles/comprehensive-guide-to-checking-and-replacing-an-automotive-drive-shaft-u-joint

Let me know.

Take care,

Joe