Contour Enthusiasts Group Archives Forums General Troubleshooting Wheel shaking @ 65-75MPH

If the brake rotors were warped from overtorquing they would vibrate during braking, mine doesn't vibrate under braking only at speed.

Being a 4x4 fanatic, I know that the bigger the tire, the greater the complexity in balancing a tire. To further, there was a company several years back that invented a dynamic Centrifugal force balancer that installed on the hub before the rim. It was aimed at the 15" 4x4 world. Well, the item never sold well enough thus the company moved on and started producing the product for semi-trucks. This was one option I considered when the vibration began but.....another frustration. In answer to the original question, the only "companies" I know of that do an on-vehicle balance are "Big-truck" companies. They're not common, but they are around. Another option I've considered but:
1. this only "masks" the real problem
2. I think this will only work if it's a tire/rim/rotor and maybe CV joint imbalance problem
what happens if one of the hubs has whatâ??s called "run-out" and "stretched" the hub (during an impact wrench tightening of the lugs)? there is no imbalance, just a wobble due to a "warped" hub spin. What happens if the bearing has such a slight mobility that it does not "screech" yet but has a little play? The play could be so small but if you take the moment arm, by the tips of the wheels the play could be substantial. My biggest fear now is that the tranny is the problem (to my understandings, A tranny spins as fast as the tire does, and at high speeds, that's pretty fast). I don't think it is but I've done just about everything short of hubs, bearings, CV joints, and the A-arm (I know the tie rods are good, they were still strong when I replaced the struts). None of the above even gives the slightest hint of failure but it doesn't mean they're not good.
I'll be replacing the 4 wheels tomorrow with those of my other contour that does NOT have the vibration. This will eliminate the fact of it being a wheel problem. Tonight, well I've got a Steering gear box on my Grand Cherokee that's been abused and is saying "uncle", sigh, another issue there.........
PS, I know I'm long winded but I'm trying to resolve this as many others are, and I don't want to be defeated but I'm losing this battle due to of cost and more so, time.

Oh, by the way, in answer to some of the other questions, my vibration started off in that it was about 75-85 and then disappeared. Currently, it is continuous up to 95, which is as fast as I've gone. It doesn't increase in magnitude at 95 anymore then it what it is at 75, that I find peculiar. The vibration began when I had about 63k miles, I know have 74K. I use the heck out of this car (I've put 32K in 15 months which is when I bought it). this is why it's so important to me to eliminate the vibration. So, for those of you that the vibration disappears after 80, this may be a sign of whatâ??s to come (I hope not).

While I agree on the "natural frequency", I can't say this is happening to my car since it wasn't there prior to 60k miles (and two of those tires are the same I have on now).

The Sears alignment numbers can be scanned and provided to you, I'll have to take time to look them up but it gives a before and after alignment numbers with some of the before in red (to be expected after changing struts) and the after all in green. I assure you, if Sears aligned it for the proper car, this wont go anywhere either.

I have stock wheels and stock tire sizes 205/65/15.

How'd one of you tag the 120 mph mark, my car has a speed governor at 111 and it works too!

I appreciate all the comments but thus far I feel I'm going in circles, I mean, I'm sure it's not the tires yet but I'm going to do a tire swap???? Maybe I'm delirious (and long-winded).

Don't waste your time scanning the alignment numbers, though they will vary from rack to rack as long as they are in the green they should be fine.

I didn't finish my jeep tonight so I may not get to the tires tomorrow, but for those interested in the dynamic centrifugal force balancers, I found the company and it appears that they are still producing the items for rims from 16"-19.5" among others.
Unfortunately, as luck would have it, I have 15" tires, thus my quest continues........

http://www.centramatic.com/

Be aware that these might be intended for a vehicle that does not have as much offset as does a contour/cougar. Key: Ask the manufacturer before buying.

If anyone should invest into these, I'm sure the "lucky" vibration holders would like to hear from you if they work (me for one)!

If anyone has anymore ideas, I'm always checking for them on this forum.

okay my understanding is this: there are certain "sympathetic" vibrations in the various suspension components that no amount of off car spin balancing can cure. the guys i used to go to, great little family shop, very, very contientious. (i moved, an advancement job wise) are a 100 miles away from me now have this elecric motor on a small cart with a rubber wheel on the output shaft. they jack your car up at each corner, mark the tire with a tire marker as a point of reference, then spin the tire with the motor/wheel set-up. this is in conjunction with a strobe light, aimed at the tire sidewall, set up to correspond with the rotation of the tire. now from here on i never quite understood what they look for or how they do it, but from that point of reference mark, they determined the area where weight was needed (always on the inside of the wheel i may add) and that was basically it. actually was cheaper than a spin balance. i hope this helps a bit, do some calling and asking around you may find someone that does this, believe me it is worth it. before i had it done, the steering wheel in my XR4Ti bounced in my hand at any, yes any speed! afterwards smooth as a babies BE-hind!

You are NOT going to believe this!! I'm still having trouble believing myself!
I changed the tires from the '97 contour over to my '98 with the vibration problem. I went out for a ride on the '98 and NOTHING. There is no vibration at all. So I say "NO WAY" and went as fast as 95 with no vibration problem at all! Still I'm not convinced so I take out the other contour with what I suspect the vibration problem and yes indeed, it's now moved to the '97 contour. I don't understand why after the tire replacement, rotations, balances 1/2 rotations. So I move the two rear tires from the 97 back to the rear of the 98 and take it out. Still no vibration, take out the 97 and this still has the vibration there either. I'm not sure if it's a rim or a tire or the combo but I do know it's something with the front two tires? I'll try a criss-cross swap and see if that does anything next. The only things I can think of is I have either two rim/tires bad on one side only or the car doesn't like having 4 Yokohomas at one time???
I'm finally nailing it, after all this time!

OK let me try and catch up with you here:
You have '97 wheels/tires, we'll call them W1.
You have '98 wheels/tires, we'll call them W2.

1. Your '98 had vibration problems, you put W1 on and the problem was solved.
2. Your '97 had no vibration problems, you put W2 on and the vibration appeared.

So one or more of the W2 wheels/tires are bad.

There is where I'm fuzzy...the vibration stopped when you put the W1 rears on the '97 or it didn't?

Sorry, guess I wasn't too clear, I was a little happy that I have finally narrowed it down.

Car1 is a '97 with no problems to date, 14" wheels+rims
car2 is a '98 with the vibration problem, 15" wheels+rims

I took all 4 wheel from car2 and swapped with car1. Car2 no longer had the vibration but car1 now did. Because I want the nicer 8" spoke rims on the car I'm going to keep, car2, and because I'm selling car1 and vibration is not a good selling point, I began moving the wheels and tires back. I decided to move the rears first and see if the vibration was still present so they were swapped and no vibration was present on car2 but car1 still has the vibration. Thus the 2 wheels that are original on car2 must be the problem.

Here's what I can't explain though, prior to all this moving, the tires were switched front to back and replaced with new ones to no avail. I even rotated the front to back on only one side and still there was vibration! WHY??? perhaps two tires on one side are bad? I criss-crossed one pair earlier but I began working my jeep, so I'll take a ride and see what results. I know this doesn't make sense and I have no sane explanation for it either but the fact remains, the vibration was isolated. It still doesn't make sense!!

I can't find a logical explanation! It just doesn't make sense. I criss-crossed one pair of tires, took it out and still a vibration. I then put that criss-cross back to the original position and criss-crossed the other set. Still it vibrates. What's going on? I have too much trouble believing it to be the rims because my original problem stemmed from the replacement of only two tires, the rear two were left untouched. But yet those two rear tires put up front don't solve the vibration?! Why did it not vibrate with the 14" tires on??? Can somebody come up with a logical statement?
Could it be that the contour doesn't like Yokohama tires in sets of 4?? I'm getting down to the wear bars on two of those tires, maybe I'll jump ahead of myself and just replace those 2 tires with some other brand of tire and hope it goes away? Geez, this is driving me nuts!!