Vibration at 70-75 MPH

[lkrasner]

For a few months now I have had vibration that sounds more or less like a bad wheel bearing at speeds around 70-75 MPH. It goes away if I solw down or speed up out of that range. Both front hubs have been replaced as they went very bad within a month of each other. Tires have been rotated with no change, so I don't think it is just tire noise.

Any clue what it could be? If it is a rear bearing going out, how hard are those to replace?

 

[TheAutumnWind]

slow down. Problem solved.

 

[OR VietVet]

Now I am confused. Is it a vibration you feel or hear? You said tire noise? Vibrations that sound like a bad wheel bearing? So do you feel it or hear it? Feel in the seat of your pants or at the floorboard or in the steering wheel?

 

[Big Buttons]

slow down. Problem solved.

Just saying but speed limits in Texas go up to 80 in some parts...

 

[TheAutumnWind]

Just saying but speed limits in Texas go up to 80 in some parts...

Ah. Sometimes I feel like I live in the wrong state.

 

[OR VietVet]

slow down. Problem solved.

"So doctor, it hurts when I do this." Doctor says, "Don't do that then."

 

[lkrasner]

Slowing down does work, fortunately, so does speeding up .

The vibration is mostly heard. I can feel it slightly in the seat and steering wheel, however it does not feel like the wheel is "shaking" like it would with a tire that was badly out of balance. It is more just a low rumble that just makes the car seem "loud". If I accelerate through this range, it slowly fades in around 70, and fades out as I get over 74 or so.

I read around online and many people mentioned this problem was caused by the torsion bar sitting against the rubber stop towards the front of the car. Sure enough, my left bar was resting firmly on it, and the right was just slightly touching. Upon further inspection, I noticed that the left side of the car was sitting about an inch below the right. I tightened the bolt on the torsion bar adjustment and was able to bring the ride height within a quarter inch, but I have the left side nearly all the way tight. The bar now just slightly touches, and the problem is still there. It seems a bit better, but it very well could be in my head.

Do I need to get an alignment now? how big of a deal is it if I put t off for a bit?

 

[ccapehartusarmyINF.(ret)]

yes i would go for an alignment depending on how yer front tires are wearing is a good indicator of how urgent it is when you drive down the road with your steering wheel perfectly straight and level does it drive straight or does it kinda pull your to one side or the other if it does this could be an indicator of excessive toe in to or toe out
if your tires are wearing more on the inside or outside shoulder you could also have negative or positive camber

---------- Post added at 05:32 PM ---------- Previous post was at 05:30 PM ----------

front end alignment is about 80 to 100 bucks

 

[afpj]

If you have 4wd, could be transfer case noise or front diff. Change fluids.

 

[WoldD90]

I've had this problem recently too... Years ago, it seemed there was a problem with the Intermediate Steering Shaft that was supposed to cause this too. Thoughts?

I am taking my truck in to get the tires balanced and rotated. I will have them check the alignment too.

 

[ccapehartusarmyINF.(ret)]

from my experience when someone says i getr a vibration at 75mph 9 out of 10 times its out of balanced tires and if they say they were just balanced i say go balance them again and it always winds up being either weights fell off or the tire installer was incompentant wich happens often hell ive balanced my own tires wrong before all though it was my first time using the spin balancer

---------- Post added at 04:34 AM ---------- Previous post was at 04:33 AM ----------

also bearings that have literally shit the bed dont vibrate they usally screech grind and sqeal at low speeds

 

[08grey]

Bad tire or bend in rim.

 

[lkrasner]

Bad tire or bend in rim.

Got my tires rotated the other day, and told them about the vibration. I wasn't due for a balance (they generally do it every other rotation), but I had them do it anyway with no change. I was told that all wheels seemed to be well balanced.

Only thing possible related: I have a sort of medium-high pitch whirring noise while driving. Sounds kind of like the noise most cars make in reverse. It changes with vehicle speed, not rpm, can be heard through about 50 mph when general noise drones it out. It persists if I shift into neutral. I'll probably make a separate post for this too.

 

[rob76]

These trucks make all kinds of sounds.

 

[DOORMAN]

Rear drive shaft could be out of balance