2001 F150 2WD 4.6 102,000 miles

All rotors and pads replaced by a shop and the trouble began. The shop swore it was my tires and like a dummie I took it to Sams and had my tires replaced.

What's been done? New BFG Long Trail T/A Touring Tires, rotors and pads were replaced a second time, new Monroe shocks and the shocks were replaced a second time, new U-joints, front wheel bearings repacked, ball joints inspected and have slight wear, new driveshaft at 20,000 miles, two new rims, two new back tires of same type, wheels balanced over and over with road force equipment. All this got rid of a dangerous shake at 67 mph but did not affect the 42 mph bounce.

I now have a pronounced bounce at 42 mph. I have an annoying vibration at 67 mph that is present 97% of the time and an occasional smooth ride for 3-4 miles on the interstate before the vibration resumes. The ride is always rough until the tires warm up. I think the vibration is caused by the road and the truck can't stop it, but I'm not sure. Three shops are scratching their heads. Any advice?

 

perhaps the shocks are not matched for the spring rate, or the springs are too hard/soft and the suspension combo cannot dampen vibratiosnn as it should? underdamped shocks will allow harmonics to ossilate

 

The shocks were matched to the under 7000 GVW according to the Monroe guidelines. I always wished I'd have seen the shocks that came off just in case they were oversized.

 

Steering wheel shake or the whole truck?
Were first set of pads worn even before you changed second time?
Didnt replace front bearings and races?
Does it pull to any side?
Vibrate in turns?

 

The whole truck, but I can definitely feel it in the steering wheel, but my water bottle shakes in the console.

The first pads were squeeking. The replacement pads had about 100 miles or less on them when the rotors were replaced the second time. I had asked for the rotors to be turned on a lathe to check them, but the shop just replaced them instead.

The front bearings and races were not changed to my knowledge.

It drives straight, doesn't pull and the brakes feel good when stopping, no chatter or vibration.

I drove it 400 miles this weekend, and it often did not vibrate when in a long steady turn on the Interstate, especially a turn to the right, but sometimes it did. I didn't include this because it did not always stop in a turn, but it did most of the time.

 

maybe wheel bearing nuts on too tight?

 

The shop that packed the bearing is a top shop, known for driveability solutions. I'll ask them to check them. Just to educate me, how would that cause the vibration?

Thanks for the help.

 

its just a shot in the dark to be honest, but if you overtighten it, the bearing housing can distort, and make it hard for the wheel to turn, creating excess heat and deformation. once again just a guess

 

Perhaps steering linkage is wore causing the wheels to move at a certain speed?

 

You had the ball joints inspected, what about the rest of the suspension system (pitman arm, upper and lower control arms...)

 

The pitman arm, upper and lower control arms have not been inspected to my knowledge, at least not mentioned to me. I had a shop known for driveability expertise check it over, and they reported that the ball joints had a minor amount of wear, so I assume they checked everything. The only thing they found was the U-joints needed replacement.

 

I know what I am going to say may not apply but it happened to me and maybe it is happening to you. I have a f-150 4x4 4.6. I had a vibration and took it to several transmissions shops without a solution. The last one figured out the problem. It seems for no apparent reason the transfer case was comiming loose from the transmission. I had the drive shaft balanced replaced all of the universal joints and was about to do what you have done when they figured it out. I got some long extensions tightened up the bolts and so far so good.

 

I've added that to my list.

I've researched the last 105 pages of problems on this site, copying anything about this type vibration into a word document that I will edit and post in the near future. The best idea for my problem seems to be this one:


Look for a problem with the brakes on one side.
Jack up the rear off the surface so the rear hangs free, block the front wheels and run the rear up in speed to see if the vibration comes in.
If yes, remove the wheels and run it up again to see if the vibration is still there.
If yes remove the drums or disc and do it again.
This eliminates or proves as you chase the problem.
It may even come down to the drive line.
Do it all safely and under control.
Good luck.


Here why I think this is good for my problem. The last shop took me under the truck while it was on the lift and an shop guy in the truck pushing the accelerator at about 40 mph. I was shown the driver's side back tire bouncing. I was then told that that proved the tire was bad. I had the tire replaced, but still have the bounce at 42 mph and vibration at 67 mph. I think the shop should have gone through this list of procedures because they told me that wheel was bouncing. What do you think?

 

Hi Wayne, that was my post sometime ago.
Same deal, the shop could not see the problem.
It turned out to be a rear drum out of round and dragging on a shoe.
Same as braking one side, it would 'torque react' and set the whole truck vibrating.
The vehichle had been rear ended and bent some things.
They just didn't go far enough and I finally had to do the testing to find it.
Good luck.

 

The confusing thing to me is this whole bounce and vibration began after I had my rotors and pads replaced. Do you think they messed up a drum?