2001 F150 crew cab, 4x4.3 months ago I replaced- outer tie rod ends, upper ball joints, lower ball joints, sway bar links, bushings, shocks, brake rotors and pads. Had the front end aligned. Last week while driving down the interstate, the front end started bouncing like crazy when I got up to about 70 mph. I had to slow down to under 60 for it to stop. Checked everything I could and cant find anything loose. Last couple of days, it started bouncing when I get up around 60. I will jack it up on Saturday to do a more thorough check. Can anybody give me some ideas on what I may want to pay special attention to? I will be checking all replacement items to make sure nothing came loose, but what else? TIA

 

what is the condition of your front drive axles/cv joints
you may have an issue with a tire on the front. can you swap front to rear and road test.
also you did not mention if the front tires were balanced with all this work you did.

 

Bad shocks can cause that issue. But you say you changed them so I am kinda lost on this one. Wheel balance is all I can think of.

 

Does one of your tires have a bubble? Are they cracked? What is the date code on them?

 

Tires look good, Didn't have them rebalanced. Don't see any abnormal wear. Its only the passenger side. CV axle was replaced on driver side. It ran fine for about 3 months. And its ok at lower speed. I will know more tomorrow when I get it in the shop.

 

My parents had an Explorer that had no abnormal wear, no bubbles, but it had cracking around the crown of the tires due to age. It acted exactly like you are describing.

 

As white just suggested, maybe tire.

My wife had a broken belt in a tire.

There was no bubble on the tire or any visual problem with the tire. Once replaced, it was back to normal. I'm sure there would have been if she kept driving on it, thank god she told me quickly (which never ever happens, lol).

 

the Brand of tire and the outside weather can really cause havoc too. My red truck has new Bridgestones on it, and I'm not happy with the higher speed ride. It's just too hard a tire for a 150, in my opinion. Especially since the weather has dropped in the mornings and when under 32, they are like a freaking rock.

My Hakkapallitta's are going back on for the winter. The BStones were fine in the warm weather, but the cold has killed their 60-70 mph drivability.

Like was said above, a broken side belt will give you a death bounce at higher speeds too. If the pressure was ever ran low, there is a fair chance than could be your problem.

 

Exactly... running a tire low wreaks havoc on the sidewall. SMA did a video about that a while back..... Blizzak's IIRC. Tire looked fine on the outside, but it was "dusting" inside.

 

Thar she blows: