Weird Vibration (LONG)

[skokie]

Ok this is not on my 68 truck but on my 97 thunderbird. I took it into the goodyear shop that I got the tires from because of a vibration that I was feeling that started at 50 (after 50 the faster you go the harder it shakes) and would act like this. You would feel a slight vibration but it works its way up to a shaking the steering wheel vibration but you can tell that is not where it is coming from. The wheel is shaking as a result. Its not coming from the front of the car. So I ask if i threw a weight or two. So for good measure they strip all the weights off and rebalance it all. I drive it off and same thing. I come back and tell them this so now they take the tires off of the rims and check for a warped rim. Everything is fine there to. So they remount the tires and rebalance same thing. According to them the tires are good. No separation , runout etc and they are balanced. Suggest it maybe a drive train issue or maybe a torque converter. So I call a tranny place that I know and tell them about it. My friend says bring it down I will check it out. He loves a good challenge He checked it out and cant find anything drivetrain wise wrong. U joints are good, drive shaft is within spec, no tranny issues etc. aka looks good. So he takes it down to another tire place for the heck of it and they check the tires. They found 2 out of balance and they correct. Well I go pick it up after they closed and same issue. So now Im almost at the end of my rope here. What the heck could be causing this vibration? Any body seen anything like this before.

Thanks

[Mechdawg]

Last time I had that issue was in my 97 tahoe. An out of balance wheel usually only vibrates bad at or around a given speed then gets better above or below that speed. In my case it got worse the faster I went. I checked it all out and found a bad u-joint. You said you had them checked but that is were my money is. Mine didnt appear to be bad until I got them off then it was obvious.

[MrC1]

I've found that these types of vibrations are usually coming from a driveshaft issue. (but you said you checked that out)

[northcountry67]

I had the same thing with a class A motorhome a few years ago. The u-joints were new and everything seemed perfect. It shook so bad that both front and rear tranny seals went out. I pulled the driveshafts and took them in to be balanced and a machinist asked me where the retaining clips were for the u-joints. It seems that the po put in new joints and on most Ford and Chevys there is a small trough that the caps go in to keep them centered. The motorhome was a Dodge chassis and required a snap ring in the outside of the caps to hold them in the center. The snap rings were not there allowing the u-joints to slide out of center. Once replaced it drove smooth. I know you said a T-Bird, but it sounds like the drive shaft is the problem.

[70c10]

Tie rods, ball joints?????

[rambler]

My tire did that, it was balanced, but ended up being a broken belt in the tire.. I figured it was the tire when I rotated them front to back, and the shaking of the steering wheel stopped, but the vibration still went on... have you tried rotating them and seeing what happens? or putting on the spare for a drive? I agree it could be adrivetraing issue, but usually its a bad tire... happend on my two of my cars..

[skokie]

Update:
I called the place that I got them and requested that all 4 tires be swapped which caused a bit of a stir but at this point I just want it fixed. The guy I talked to said that he doesnt have a machine that can check the tire for runour or if its warped but he sent me to another store that does. Now that brings up something here, If he doesnt have any equipment that can tell him if a tire has excess runout or if its warped then how can he tell me that they were good in the first place? So now its at a shop that has that equipment so I should hear something in a few hours. Will update this post once I have some new info.

[Luvlegs]

Same issue - several times myself
1) was a bad belt in tire (mazda)
2) cracked rotor (mazda)
3) broken engine mount (chrysler)
4) bad ball joint (chev truck)
5) loose caliper and broken brake pad (pontiac) I hate trying to locate vibrations but I'm getting good at it! Good luck!

[68/72parts]

Hey guys I work for a tire center and if there is any kind of competent tire guy at your store they should beable to tell you if your tire is seperated or out of round just by putting it on a balancer! If you have had them balanced twice and there was no change? it could be something else, but it sure sounds to me like its tire related. Try rotating the tires and see if the vibration changes any. If your tire store is any good they should be more than willing to try another set of tires and see if that solves your problem. What type of tires are they, and if you need any other tire help or questions feel free to P.M me and I'll be more than glad to help out.

[truckdude239]

Originally Posted by 68/72parts

Hey guys I work for a tire center and if there is any kind of competent tire guy at your store they should beable to tell you if your tire is seperated or out of round just by putting it on a balancer! If you have had them balanced twice and there was no change? it could be something else, but it sure sounds to me like its tire related. Try rotating the tires and see if the vibration changes any. If your tire store is any good they should be more than willing to try another set of tires and see if that solves your problem. What type of tires are they, and if you need any other tire help or questions feel free to P.M me and I'll be more than glad to help out.

i work for sam's club tire and battery center warped rims and bad tires show themselfs on the balancer the rims if warped will look liek they are woppling and you can normally feel a bad tire when it is spining on the balancers with your hand

[68gmcdually]

We had a customer's car like that and we found that he had the tires rotated somewhere else and the put them on incorrecty. His tires where directional and made the car have a slight shimmy. Probably not the problem but I thought that I would offer it up.

[ChevLoRay]

I put a new set of tires on my Tundra. It seemed to shimmy a tiny bit, so I had it aligned. Better, or not? I couldn't tell. So, I went back to the WalMart where I bought them. They checked the balance on all of them, said that the balance was off just a little, and I took off, again. Still, something didn't seem right. So, I went back. They re-checked the balance, again, saying that they had some balance issues. Then, they rotated them. At that time, the tires didn't have 1K miles on them. Now, the previous sensation of shimmy, became a slight bounce in the rear end. Back to WallyWorld. They checked them and determined that one of them was out of round. So, for less than $5, I had a new tire.

My thinking is this: If a tire is out of round, out of balance, or whatever is causing the shimmy/bounce, it will ultimately affect another tire. Once the new tire was on the truck, and I had driven it for about 1000 miles, I either got used to the ride, or it was better.

This was on a set of Continentals, following a set of Michelins. From one brand to another, you will feel a difference in tires, even if they are the same size. I had also put a set of Continentals (LT235-15's) on a '96 SilverDollar, and they were so much better than the Firestone Firehawks that had been on it. With an 80K mile warranty, I'm satisfied, for now.

So, that brings us back to your problem. You can see that it took 3 trips to find the out of round tire. It isn't common for these Continentals to be out of round, so they didn't think of it as soon as I did. I had previously replaced my steering rack mount bushings with urethane items, so that wasn't an issue.

But, do you know if the tire store checked for out of round? If not, it's worth checking. Usually, drive line vibrations won't "just show up" when you get new tires. How many miles on these new tires? Has anyone checked the run-out on the wheels? It should be obvious to the installer, when they spin 'em to balance them. Have you, or another driver, flat-spotted them in a panic stop? I am sure the answer will be a simple one, once someone figures out what it is.

[skokie]

Originally Posted by 68gmcdually

We had a customer's car like that and we found that he had the tires rotated somewhere else and the put them on incorrecty. His tires where directional and made the car have a slight shimmy. Probably not the problem but I thought that I would offer it up.

BINGO!!! You got it!! Turns out that exactly what it was. When they told me I couldnt believe it until I called a ford dealership and the parts guy said yep they are directional. However the saga continues. There is a still a vibration from 65-75 but (weird part here) only after its been driven 10-15 mins. Im guessing that is how long it takes to get the tires warmed up and maybe since they were on the wrong side for a while that some damage has been done. Taking it back tomorrow so they can "decide" what they want to do. At this point since they found it and it was their sister store that installed the tires I would say that they are liable. Not trying to be a jerk or anything but these are pretty pricey tires. Goodyear Comfort Tred. Will update this tomorrow once I have a answer from the shop.

Thanks for all the tips folks. Greatly appreciated.

[68gmcdually]

Geez, glad I could help for once. Good luck.

[skokie]

OK update time. Well the tire place that said all the tires were good was wrong. I took it to another goodyear and all my tires had excessive runout and all 4 were replaced. I still have a slight vibration in the rear of the car so I think I am going to take it to a driveshaft shop to get it checked out.