Vibration

[Double L]

I got a 89 Ford F150 5spd manual. I noticed yesterday I got a vibration whenever I go 55 and faster. Anything after that you don't feel a vibration. I checked my tire pressure and noticed the left rear only had 20 psi when it should have 50 psi so I put air in the tire and it still does it. I'm thinking the driveshaft or the rear end is about to go out. What do you guys think?

[Larry Heyns]

Shake the U-joints and yokes by hand. Have a tire store look for the leak in the left rear tire. They may discover the tire has cord separation and cannot be balanced. Jack up each wheel and check the wheel bearings by shaking the wheel and rotating it slowly to feel for drag. It seems that the rear end would whine if it was going out. A drive shaft could have been "twisted" if you were abusing it. That would cause a vibration, and would not be visible.

[Double L]

I just had to go fill up the rear tire again, it went down to 45 and should be at 50. I filled them all up a couple weeks ago and the others are holding 50psi just fine but the left rear is losing air. Wouldn't surprise me if the driveshaft was twisted cause I had two loads of snow in it during the winter when it snowed and I helped some people move and she was loaded pretty heavy each time! I do know though the brake drums on the rear had got stuck on the truck before but I don't think that would cause the vibration, I do know whenever it rains hard the brake and rear abs light comes on and stays on and I just replaced the rear abs sensor. I should of bought a Chevy/GMC!

[DaveFromColorado]

well, I'd bet it's either the U-joints going bad, or the rear-end was a bit stressed.

When you have uneven tire pressure on your main drive-tires you'll create a difference in speed between the two sides, this will cause the little spider gears inside to spin more than they should - this spinning can (and will) break down the fluid in the rear end. If I were you, I'd change your rear diff fluid, and inspect/grease your u-joints. Make sure you get a tube of "friction modifier" for the rear end - (I use EquiTorque ... not sure of the spelling you can get it at Pep Boys, Checker, Schucks, Kragen, Autozone, Car Quest, Napa or whatever other parts store you've got available) add the modifier to the rear end BEFORE filling with fluid - they say you only need it with limited slip rear differential, but I find it makes ALL differentials run smoother. I also only use synthetic in the rear ends, it holds up better to the type of abuse I can deliver.

--Dave.

[Mr. Ford95]

One of the simplest and cheapest things to check, get your tires re-balanced. Do all 4 of them and like Larry said, get that 1 one that is leaking taken care of and then see what happens. Do you feel it in the steering wheel or just in general? Could be a tire that has worn funny. I have had trucks where the tires started cupping out and it would vibrate like crazy while others wouldn't vibrate. Some out of balance that you could barely feel and others that vibrated like crazy.

My wife's Fusion has a small vibration but I have yet to track it down. Don't feel it, but you can hear it. We had just rotated the tires and when your doing between 15 and 30 you can hear it. We are thinking it could be the tranny starting to act up, my brother's F-150 just lost it's tranny 3 weeks ago at 38K.

[Larry Heyns]

Rain is one thing, but the ABS sensor can react to a bad wheel bearing or hub. Jack it up and check them out.

[Double L]

I appreciate this ALOT! I feel it somewhat but I can hear it. At first I thought it was the drive shaft but I picked up speed to about 65 and it still did it. It didn't get any worse but it does start at 55, anything under 55 and it runs just fine. I only had the truck since january and not sure when the rear end fluid was changed so I better do that and get some grease for the u-joints as well. I'm about ready to get rid of it anyway for a newer truck. But I want to get the kinks out of it before I do!

[DaveFromColorado]

Mr. Ford ...


sounds like cupped tires - if you can hear it, but not feel it, it's most likely in the rear. This could be due to a bad alignment on the front end, or bad ball joints (common on many cars with todays pot-hole free roads everywhere) and when you put the tires out back, the cupping came through as a vibration or hum. This is also a sign of a wheel bearing going bad. Most often you hear it before you feel it.

--Dave.

[Double L]

On the road I turn on to go to home from the highway there is a long pothole where the concrete and asphalt meet and it's rough and does jerk the wheel. So wouldn't surprise if there is damage done from that, like I said it just started yesterday when I was coming home from school. I'll let ya know what I find out. Now I need to check the air in that rear tire!

[DaveFromColorado]

have a shop check the ball joints on your truck - they gotta be loaded up to be checked right, so it's best to just have a shop do it - that can cause strange vibrations, but not quite the same as what you're describing.

--Dave.

[Double L]

I appreciate the help guys! I enjoy working on cars and stuff like that but I wanted some other opinions cause this one stumped me big time!

[Mr. Ford95]

Ha Dave, that was something I asked her. Said she doesn't remember hitting any holes. Alignment still feels good, pulls the same amount and the same direction as before. I'm thinking it's that the rear tire being moved to the front just has a funny wear to it that needs to be wore in.

Don't think it's a wheel bearing, I have had one go out on a 2000 F150 in the left front. Heard that thing let go, it made a horrible squel of metal on metal.

[Double L]

I do know it likes to drift to left side. Also I notice it to whenever I brake but then again it's been doing it since I bought the truck but I never worried or paid attention to it. Another thing I noticed was that whenever I slow down for an off ramp at 65 mph and hit the brakes even at 45 mph I can feel the truck vibrate and shutter. I never felt it in a newer car and thought it was the abs kicking in and out. I never worried about it cause the brakes work fine but figure I'd ask anyway!

[Uturn2001]

Have the tires, brakes, alignment and U-joints all checked out as soon as possible. From what you have described I would be surprised if it was just one problem.

My initial guess would be:

I do know it likes to drift to left side.

Alignment

Also I notice it to whenever I brake but then again it's been doing it since I bought the truck but I never worried or paid attention to it. Another thing I noticed was that whenever I slow down for an off ramp at 65 mph and hit the brakes even at 45 mph I can feel the truck vibrate and shutter.

Bad brake pads and very likely a warped brake rotor/drum.

I noticed yesterday I got a vibration whenever I go 55 and faster.

Could be U-joints but I would be willing to bet it is a tire problem. Could be severe cupping but I would lay money on a slipped belt if not both. U joints usually smooth out at higher speeds where as tires tend to get worse.

You can feel cupping by running your hand over the tire, but the only way to really tell if a belt is slipped in to freely spin the mounted tire and watch the tread from straight on. If the whole tires looks like it is rolling true and the tread wavers back and forth you have a slipped belt.

[Double L]

I just noticed the outside tread on my passenger side tire is starting to get off! Looks like it's times to get some new meat on the ground! Also on with the brakes my other cousin who had the truck before my other cousin said that the rear brakes got stuck on him one time before! I'm starting to wonder if that is why my brake and rear abs light is on but he told me the truck wouldn't move when they got stuck that one time. I'm starting to regret buying the truck off my cousin but for $1200 and I needed a vehicle at that time I couldn't pass it up.

[Double L]

I'm starting to think the tire is the problem! I need to tomorrow inspect the tire real good to see if I hit something with it. I appreciate y'alls advice and opinions! Now how much do I owe y'alls?

[mdgardner963]

if it only happens at certian speeds it is 1 or 3 things.

Alignment
tires
balance

Thats all folks.

[Double L]

Thank ya MD, now y'all didn't answer my question, how much do I owe each of ya's! I'm in one of those comedical moods today! 8)