Could be u joints, lost a tire weight, driveshaft out of balance...

Anything that spins could cause it

 

How can I tell if its u joints. Just sloppy or am I looking for a spot during a full rotation?

It feels too distinct of a spot to be an out of balance tire but I guess I would have them all balanced again If I cant find anything else.

Thanks,
Bill

 

A slight flat spot on a tyre is very hard to detect unless you have an alignment machine.

Check for stones or mud stuck to the inside of the rims, or on the drive shaft.
This could also make them out of balance.

A bad engine mount could also give you a vibration.

To check the uni's, all you have to do is shake the tailshaft and see if there is movement.
There should be none or very very little.

Really it is a process of elimination.

 

While you're checking the tires look for a blister on the sidewall as well. It's less likely but that would feel like a flat spot as well.

Make sure to look at the back side of the tire too. They like to hide where you can't see them.

 

Does the vibration disappear after a bit of driving. Nylon corded tires will have flat spots until warmed up. Generally these would be older tires. Just a thought.

 

DOT "slicks" like you use for open track events do this too.
The longer they sit, the worse it is.
Goes away once the tires warm up.

 

My father in law parks his vehicles on carpet folded over 3 or 4 times to minimize flat spotting. He says it works hope this helps.

 

Front, rear, left, right? Feel it in the steering wheel or on the seat of your pants? How old are the tires? Anything recently replaced in the suspension?

 

Seems like right front but not sure. Definitely seat of the pants. Tires, wheels and suspension is all new.

Thanks,
Bill

 

Maybe rotate the tires and see if the vibration changes location? Spindles in good shape with new bearings?

 

Maybe rotate the tires and see if the vibration changes location? Spindles in good shape with new bearings?

^ Agreed. The bearings (or a worn spindle) could be the culprit.

 

I've had a bubble where the tread separated from the carcus in one small area. Say about two inches square. You have to really be looking for it to find it. The area will stick out slightly more than the rest of the tread. Happened to me five times but mostly related to freeway driving and desert heat.

 

One idea that hasn't been mentioned yet, front wheel bearings. A few years ago I had a vibration that I chased down. It ended up being a galled bearing race in an outer front wheel bearing. I assume it was a metallurgical issue or flaw with the rollers themselves as the other front bearing races (all Timkin) were fine. Note my diagnosis included, tires, friction modifier for the rear end, u joints, drive shaft balance, and yoke wear. I was about to pull the axle shafts and pumpkin when I spun the front wheel and felt the flaw. Pressed out the damaged race, pressed in a new one, packed the bearings and all was well.

I should note that when you go to the local parts house often enough, they get to know you. In this instance, it was a Sunday and they were short handed at the counter so my counter guy pointed in the direction of the back room and said, the press is in there, go ahead and press the new one on yourself!!!

 

Bent wheel from hitting a bump too hard feel like a flat spot too.


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Tires

Sounds like a tire is starting to separate, jack each wheel up and spin them very slowly and carefully you'll find it.

 

Thank you all for your responses. While poking around today I think I may have found some other issues I need to address first. Maybe there is a shot they are related. I will start a new thread.

Thanks again,
Bill

 

could be flat spots on the road