hey guys i have a 79 f150 4x4, i have a new rebuilt 400 with about 1500 miles on it now, when i'm driving down the road i've noticed that at about 65+ i get a noise/vibration that sounds sort of like the base in a speaker, also you can "feel" the vibration when you let off the gas, the truck accelerates fine and i was going upwards of 85-90 no problem, but i want to know if this is steering related or u-joints, so i can fix it before it's completely gone. i have 33x12.50s if that makes any difference. thanks for any help.

 

Well the saying goes if you feel it in your but it is coming from the rear, I would jack up the back of the truck and start wiggling stuff around

If it is coming through the steering wheel it is more likely in the front

 

well i can hear it more than i can feel it

 

Do you have some stock rims and tires you could throw on it and see if it goes away?

 

no, also when i'm driving at low speeds in a straight direction or turning/driving to the left there is a noise, it sounds like metal on metal or some kind of whirring sound, could these two things be related, when i make a right turn this low speed sound immediately stops and then returns when i go straight/left, could this be steering, i don't know much about the steering components so please help me.

 

From the sound of your last post it sounds like you may have a wheel bearing going bad,jack up the front end and wiggle your tires back and forth and up and down,and spin the tires and listen for any grinding noise.If they feel loose or grind,that should give you a better idea of what is wrong.If when you are wiggling them there feels like there is some slop have someone else wiggle them while you look at your steering linkages to make sure they are not worn out.

 

Either that or a driveshaft problem ...like U-joints installed backwards

 

how hard is it to replace the wheel bearings in the front, do i have to take all the brake stuff off
how can i check the u-joints
i know my steering dampener is not working, could this be part of my problem
thx

 

U-Joints,

Block the truck, put in neutral, and get under and twist, move drive shaft .... any play or movement means new u joints (not that hard of a job).

Wheel bearings are behind rotors .. so have to remove. For the wheel bearings the hardest part is removing bearings and properly replacing.

Jay

 

If you have never R+R'd wheel bearing's or are not real experienced I would take the rotor's to a shop and let them swap out the race's.

 

i recently had brake work done, i told them to replace all pads and rotors, calipers, would they have put new wheel bearings in also?

 

Good question, depend's what kinda truck you got. 2 or 4 wheel drive. A 2WD rotor come's with new races but not bearing's. 4WD it is just the rotor only. Unless you specified to the shop I doubt they put new bearing's in.

 

[QUOTE=ranger429] A 2WD rotor come's with new races but not bearing's.

Yeah they come with races but these are absolute junk. These are cheap races installed at the factory used to machine the rotors and are not intended to be installed on a vehicle. If you replace a rotor you should put your old races in from the old rotor along with the wheel bearing if they are still good, otherwise replace with new parts. The bearing and races are sold as a matched pair for a reason.

 

i checked my rear u-joint today, there was a little room, but it was so tiny i don't think it means anything, should i drop my truck off at the shop and have them check bearings, what's the worst case scenario if i don't get this fixed before another long trip and it's bearings?

 

my dust shields are pretty beat up could they be responsible for at least part of my problem?