Hi, I'm brand new to this forum, but have been reading lots of posts. I have a vibration on my 99f150 5.4l. It starts coming on at about 62mph and is worst at 65mph and seems to calm a bit after that, but doesn't go away. It is related to wheel speed not rpm because it is the same on acceleration or deceleration. I just got new tires (goodrich long trail at samsclub) had them rebalanced twice... i can't say whether it was there before the tires or not, but i don't remember it . The tire shop (samsclub) said i have some play in left front wheel bearing, i jacked it up and it isn't bad. I seem to feel it in the seat more. I haven't jacked up the rear end. I was just wondering what you guys could suggest for possiblities. I'd like to take care of this myself instead of going to ford... because I've read lots of threads on here where even ford couldn't figure out vibrations. I also noticed today that I drove the truck cold on the freeway for about 15 minutes and it was not as bad, then i stopped at the store for 5 min, got back on the freeway and headed home and it was much worse. Don't know why hot or cold would make a difference.... any suggestions would be greatly helpful... btw the truck has 67000 miles on it has really been taken care of, I'm the second owner and just got it a couple months ago. I think i'm going to try checking the passenger spindle nut for looseness today and then go to samsclub and have the tires rotated to see if that changes the vibration at all. Thanks so much.

 

Tires need a re-balance.

 

Check tire pressure and make sure they are all the same. Also I had a driver side rear brake dragging which caused a vibration, took the wheel off and all looks fine but replaced the pads anyway. Next time you drive feel the temps of the wheels and you'll know if ones dragging.

 

How's your u- joints? I had the same thing going on and it was my front u joints stating to go bad....if it ain't that one of your wheels my be bent. I had a buddy with that problem.

 

tell us more about your truck. does it have aftermarket rims, different size tires, 2wd-4wd, stock -lifted, etc.

also, honestly to me it sounds like one of these choices to check out:

tires need to rebalanced.

rims are bent.

tires are out of round, bulge in tread, start of seperation, etc.

since you feel it in the seat it is a rear issue. if you felt it in the steering wheel it would be the front.

 

The OP has another thread going on the matter -

https://www.f150online.com/forums/19...ion-65mph.html

Hey , isn't there like a "Road Force Balance" ? I know there's a Static Balance, but is the "Road Force" deal something you have to ask for when taking a vehicle in for a 4 wheel re balance and/or vibration problem ?

Yea, the OP doesn't have an LS rear end either, -if that makes a difference. It is a 9.75 tho. I initially thought it was rear end shake, -fluid/modifier break down. If anyone has info about balancing options, please post in the above thread, thanks fellas.