Rhythmic shake/bump 2002 F150


#1

I have a 2002 F150. Small V6 regular cab 8 foot bed 2 wheel drive.
In the last couple of months it has developed a rhythmic shake that is more like driving over a bump. It is really quite similar to driving on a road where all the release joints have been recently tarred so you go over a slight bump every second or two. I actually tried to convince myself that is what it was for about a week. Seems to be coming from the front driver seat.
I previously lived in Mexico and the pot holes there would occasionally shear the bolts right at the lug nuts. Not too different than a car that was damaged like that, but I checked the lug nuts and it seems ok.
The bump does not transfer into the steering wheel.
Being a 14 year old ford the motor doesn’t idle as smooth as my wife’s new Toyota, but not bad either. If I let off the gas the bump doesn’t stop. I haven’t changed into neutral while it is running to see if that stops it.
Tie rod?
Axle?
Can anyone tell me what to check or if there is a picture of something I could post that might tell you what is wrong?
Planned on a camping trip this weekend with my wife. She is going to be ticked if we have to cancel.


#2

Not sure if a cancel is necessary but new shocks and an alignment would be a good start.


#3

From recent posts here I saw a vibration caused by a bad torque converter. That was kind of a new one to me but there are plenty of old ones to go to. There’s the universal joints, center bearing if there is a two part drive shaft. Then there is the differential with the wrong type of fluid or the right type of fluid without the right additive. Bad tires and a hanging transmission mount come to mind and tell us what the problem was if it is ever fixed.


#4

Check the rear wheel bearings…


#5

Check the tires. A broken belt can show up a a rhythmic bump. So can a bent wheel that wobbles.


#6

Ford trucks tend to have problems with the drive shaft lube going dry, especially where it splines into the transmission, so good idea to check that. I think Ford recommends a specific grease to apply there. Also problematic brake rotors could cause this. Ask your shop to check to make sure the two sides of the rotor are parallel to each other, with the run-out on both sides within limits.