I replaced all 4 of the tires on my 03 6.0 F250 CC a few months ago at a local tire store. Within a month I noticed a VERY BAD vibration which I could feel all the way through the steering wheel (when I "hit" the "magic" speed it felt like I was going to bounce off the road). This problem happened every time I got to 50mph and would completely vanish after I got past 50mph. I took the truck back and let them rebalance the tire thinking that it was just an out of balance issue. After the tires were rebalance the problem had moved from 50mph to 55mph. I went in and had the alignment and suspension checked and everything was fine. I was just about to go back to the dealer to have it checked out but went back to the tire store one last time to have them check it again. A supervisor from out of town was there that day and heard me explaining my problem. At that time he told me he knew exactly what it was. He said the tires needed "ride matched". I had never heard of this before so I asked him what it was.

This is basically what he said:

"When a wheel and tire are mounted together they are seldom joined at the one ideal spot. Each of these units, though it may be built to specification, frequently adds to the slight error of the other and together they can generate a vibration you can feel. "

"Lateral and radial rim run-out are other causes of force variation that the system isolates"

I still don't really understand exactly how the "other" machine they used on my tires works but ever since they did the ride matching the vibrations are completely gone (and I am a "happy camper" once again).

I have never had this problem on any other vehicles I have owned (although I'm sure there are others) but just wanted to mention this in case someone else develops a similar problem with "very strong" vibrations (or "shudders") after a tire change.

 

I have had a few of these in my time, that was a very good explanation he gave you. Unfortunately, not in simple terms. The way I explain it is that humans cant make anything perfectly round. Lets say both wheel and tire are egg shaped, and you mount them with the high part of the "egg" in the same place. The fix is to dismount the tire and rotate to a better spot, then rebalance

 

To aid in proper balancing, new tires have a mark (point of lightest weight) for the technician to use.

Static Imbalance: Vertical movement resulting from heavy or light spots in a tire.

Dynamic Imbalance: Lateral movement resulting from unequal weight on both sides of the tire and wheel/rim assembly’s circumferential centerline.

Run Out Imbalance: Excessive radial and/or lateral movement resulting from tire or wheel/rim non-uniformity, improper bead seating, or improper match mounting of the tire and wheel/rim assembly.

Vehicle Imbalance: Vibration due to faulty vehicle components other than the tire or wheel/rim assembly; such as hubs, brake rotors and drums, and drive lines.

Hope this helps, just balancing a tire is not so easy.

 

wizard, great post. I purchased a set of Michelin tires for a '97 Explorer that I used to own because the 1st set ran really quiet and smooth at any speed, but the new set of tires vibrated pretty bad. I had the tires rebalanced no less than 3 times and the problem never did go away. I just recently replaced the Goodrich T/A's on my '03 6.0 because of the great wear and ride I got from the 1st set and I can report that the new set are just as good. Thanks for the info.

 

the industry term is called "road force balance and indexing" works great. Glad your problem is solved