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Vibration at certain speeds, not engine speed related


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2000 OBW manual, 270k miles

I noticed an odd vibration into a long trip. only at ~55mph. threw it in neutral, still there at same speeds. a few hundred miles later (no choice weekend trip and no where to get them checked), it was spreading through a larger range of speed, 50-65.

Got a rotation and balance, they said it was good but tires were wearing way too fast. 35k into an 80k tire and near the Wear Bar

Last set of tires was fine and outlasted the 60k rating by 10k. said wear was even, didn't appear mechanical.

 

-Could this be a bad tire? that didn't show in spin balance

-if not what is it? could it be?

 

Mind you I am super anal about rotation, balance, and mileage. none of these showed any change.

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I am thinking you may need a 4 wheel alignment, because out of alignment can cause abnormal tire wear, even while the tire is still balanced. Does your car steering "pull" to one side or the other while driving? If so, that is one sign of a bad wheel alignment.

 

Since you are down to the tire wear bars, you prolly need to buy a new set of tires. I know.........not what you want to hear with 35K miles on 80K mile rated tires.

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no pull.

I will get some credit on the tires, so not a big deal.

Still no reason for the vibration at certain speeds though?! could a bad belt that doesn't show in the spin balance explain. not from what I can figure.

 

anyone?

 

Yes, I think a tire could balance good, even with a bad belt. A bad belt certainly could cause the vibration that you have described. I am thinking a new set of tires will solve your problem. Prolly, still recommend a 4 wheel alignment even if you are not getting a "pull." My guess is that it has been a long time, and a lot of miles since you have had a wheel alignment. Once done, you will know that your tires are running good and straight, and true, and that you will be getting your best tire wear in the future.

 

I keep my tires pumped up, and check them once a month making sure that all four tires are pumped to 35 psi on my OBW. I have one of those cheap 12v cig lighter powered air pumps. It does a good job of pumping up my tires on the driveway.

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right on!

yupp, it's been a time since I had the alignment done, like 100k+. but squeeky wheel, no probs = no reason.

I run around 35 in the summer, lower in the winter, just in case I hit some slick spots.

I am unclear as to why the wobble or vib wouldn't show on the spin balance at Discount Tire. can you tell me how that works?

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right on!

yupp, it's been a time since I had the alignment done, like 100k+. but squeeky wheel, no probs = no reason.

I run around 35 in the summer, lower in the winter, just in case I hit some slick spots.

I am unclear as to why the wobble or vib wouldn't show on the spin balance at Discount Tire. can you tell me how that works?

 

I love Discount Tire, they do excellent work I have found. Spin balance is exactly that. The tire/wheel is spun at fairly high speed. Sensors pick up info out of balance situation, that will show the tech guy where to add a lead weight(s) to the wheel to regain balance. So by definition, it is more of a wheel balance then a tire balance. If in deed you have a tire with a broken belt, the tech guy doing the balancing, should be able to see tire wobble as the tire spins. Next time at Discount Tire, ask if you can watch a wheel being balanced. They will prolly let you back in the shop to watch it being done.

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Most certainly a tire with bad, broken or shifted belts can balance out fine. Its the tire not rolling true with weight on it that causes a vibration at certain speeds. It can wobble slightly, or be out of round or have what is called force variation problems from improperly overlapped belts. Tires take a lot of abuse, and you can get brand new tires that have belt issues because tires are still made by hand in that the belts are all layed within the tire mold by a person and that can cause in-consistancy from tire to tire. It happens across all brands but is more prevelant on the cheaper / lower end tires and not so much on the premium / high end like Michelin.

 

Also all balancers are not created equal and not all shops care about precision balancing a wheel / tire either.

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The speed at which the vibration occurs can change as well as the belts can shift and squirm within the tire as it is rolling. I've seen them produce physical knots and bulges on the tread at their worst -- basically the tire was ready to fail or blow out at that point.

 

Most people are riding around on tires that have one problem or another that doesn't affect the safety of the tire but gives them a less than comfortable ride, and they just don't realize it.

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Thanks

yeah, hand made costs more. I avoid hand made as machines really never have "bad days".

These tires are Pirelli cinturato. they weren't cheap, but not super premium either.

 

thanks and I will let you all know if a new set, NOT PIRELLI this time, clears it up.

I was hoping that a rotation would help me find the problem tire, but I can't pinpoint it. which is odd

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Worn ball joints? Especially with that mileage.

 

They could cause the tire/tires to move at certain speeds. Does the front end "clunk" at all on bumps or un even terrain?

 

This could cause funny tire wear as well. The car would also theoretically align fine too because the ball joints would be loaded down.

 

?

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Worn ball joints? Especially with that mileage.

 

They could cause the tire/tires to move at certain speeds. Does the front end "clunk" at all on bumps or un even terrain?

 

This could cause funny tire wear as well. The car would also theoretically align fine too because the ball joints would be loaded down.

 

?

 

 

I have not noticed any clunking.

the tires ARE wearing EVEN though.?

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Worn ball joints? Especially with that mileage.

 

They could cause the tire/tires to move at certain speeds. Does the front end "clunk" at all on bumps or un even terrain?

 

This could cause funny tire wear as well. The car would also theoretically align fine too because the ball joints would be loaded down.

 

?

 

Very good advise, suggest you put the car up on a lift, and have mechanic check front end suspension, ball joints, and tie rods for "play." Any worn suspension parts can cause vibration. However, I still think your tires are the cause of your problem.

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All tires have their belts hand layed up in the molds. The difference is in the tolerance specs for the mold for the finished product. Michelin has the tightest tolerances of all manufacturers and is a pricey tire. Do they make the best tires? That is subjective, however I have found that I have found that their build quality is superior so they have the least problems.

 

That being said, if you have more than 1 tire that has a problem rotating may not help you find or pinpoint which one it is. Premature wear can be suspension problems or just a matter of the tire rubber compound not being right. You'll never know that, the manufacturer won't admit it and neither will the distributer/installer.

 

If your tire wear is even and smooth on all 4 with regular rotations chances are it is just soft rubber, notwithstanding the tire mileage wear claim. You do have a lot of miles on the car so confirming that you also do not have worn parts is also prudent. A car cannot be properly aligned with worn parts and a good alignment tech should be able to pinpoint the problem area during the process.

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OK, I got a new set of Michelins. Vibration is still there at same speeds, ~30mph and 50-60 mph, whether in gear or coasting.

I have an appointment to get it in the rack Saturday morning. I'll post an answer. If / When I find one!

 

positive though is that the Pirellis cost me $30 to run for a year, 37k out of teh 80K rating with a rebate and 251$ credit.

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Try and find a used driveshaft? I'm surprised that no one bothered to check all the rotational items while it was on the rack for the tires--especially when one of the complaints was a vibration. Checking for other causes was always a standard procedure when I was working on the line no matter what shop I worked at.

 

At least you didn't have to bear the cost of a complete set of tires. That vibration from the driveshaft should have been a "seat of the pants" type. If rotating tires f/r or s/s didn't change location/frequency you usually can rule out tires.

 

A lot of times we would swap the tire/rims on the problem car with a known good set to eliminate them as the problem. Of course easy enough to do at a new car dealership. Driveline vibrations can sometime be a B to find.

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