Highway Speed Vibration

Topic: Highway Speed Vibration (Read 4303 times) previous topic - next topic

Highway Speed Vibration

June 05, 2009, 12:05:34 PM

Trying to track down the cause of a highway speed front vibration. Don't notice anything until speeds above 55 mph...more pr0nounced at some over others. Seems to be more pr0nounced on the passenger side. It's a "harmonic" vibration in that it's not constant...gets pretty bad (shakes the dash and glove box - not enough to cause a CD to skip, though), then gradually subsides to nothing, then starts coming back.

I replaced the struts and strut mounts this spring, and that did not make any difference. I've had numerous alignments and wheel balancing with different sets of tires and that has never made any difference either. The shop guys have never indicated ball joints or tie rod ends are bad (and on my T-Bird, the shop I took that car to wouldn't do an alignment if the ball joints and/or tie rods were bad). All of these items, ball joints, tie rod ends, etc. are original, though (as far as I know). I had the front wheel bearings re-done recently as well.

Thoughts on what I should check, or what might be the problem?

I was reading the thread about the "clunk/pop" noise and think there are some valuable checks listed in there?

Thanks!

Highway Speed Vibration

Reply #1 – June 05, 2009, 12:22:22 PM

I'm going to bet........driveshaft issue. How are the u-joints? Is the shaft out of balance or bent? Bad u-joints or a driveshaft out of balance/bent will cause a vibration that comes and goes at high speed.

If it is a front issue it could be the control arm bushings or a bad wheel bearing. They usually constantly vibrate though....

Highway Speed Vibration

Reply #2 – June 05, 2009, 12:35:05 PM

I was considering the driveshaft as a culprit, but haven't checked it. AFAIK, the u-joints have not been replaced. Is there a good way to check them? I've never replaced u-joints, but I understand it's not all that hard. Any thoughts? Should I get greasable ones if they're available?

Highway Speed Vibration

Reply #3 – June 05, 2009, 12:55:40 PM

I just take the driveshaft out and have the u-joints replaced. It's easier than pressing them out at home plus the cost to have it done is less than $100, even if you bring the whole car in. The easiest way to check them is to go under the car and try to wiggle the drive shaft back and forth with the car in park. There should be no to very little play. Also while you're under there check to make sure that you aren't missing any balance weights on the drive shaft.

Highway Speed Vibration

Reply #4 – June 05, 2009, 02:17:56 PM

A driveshaft issue would feel more like a rumble, as it's a first order vibration (much higher frequency than a wheel related vibration). I just had to repolace the driveshaft in my T-Bird because of a rumble.

In my experience a vibration that comes in waves like that is almost always a wheel or tire issue. You say you've tried wheel balancing and even different tires, but have you tried rotating the tires? Move the front tires to the back and see if that makes a difference. Your problem could be in a bent or out of round rim. Of course it goes without saying to make sure there are no clumps of dirt or grease on the inner rim causing an imbalance. Also look for signs of wheel weights coming off - even if you just had a balancing you could lose a weight minutes later.

Also, were the different tires you tried brand new, and were they a quality name brand? Old tires could have broken belts or be flat spotted from a panic stop, and cheap new tires could just be poorly made. When I worked at the dealership we sold cheap Korean tires for the snow tire program, and sometimes we'd have customers come back several times and we'd try several tires on their car before we found a set that didn't vibrate. This happened more than once, on more than one car, so it's not as uncommon as you might think.

Highway Speed Vibration

Reply #5 – June 05, 2009, 07:24:30 PM

X2 on the bent rim. I had a bent rim on my wife's neon. I couldn't get fir of the shake in the steering wheel. It got about 10 times worse when I changed it from the back to the front. The rims looked fine, I couldn't find anything wrong with them.

Highway Speed Vibration

Reply #6 – June 05, 2009, 07:58:31 PM

Quote from: Thunder Chicken;276042

we'd have customers come back several times and we'd try several tires on their car before we found a set that didn't vibrate. This happened more than once, on more than one car, so it's not as uncommon as you might think.

I was one of those people and I bought Michelins doubt I would again, but that is another story. Find some one with a GSP9700 balancer
http://www.hunter.com/pub/product/balancer/4159T/index.htm

They check the wheel for round and duplicate road forces, plus they tell which corner of the car to put a tire on for least vibration. If you find someone with one of these who knows how to use it and is willing to take the time to solve your issue they should be able to find the problem if it is wheel / tire

Highway Speed Vibration

Reply #7 – June 08, 2009, 10:24:40 AM

Thanks to all who wrote. I will look into both issues. The tires on the front are/were VERY lightly used "Big O" tires. Story was that I made an appointment to their store for a ordered set of the BFG 225 60-15s to go on the front. Well, turns out they didn't get them in because they're "a hard size to get now". Supposedly told me they left me a message, but I never got one. I was not happy. I was leaving on a trip that Saturday and this was Friday afternoon. Sooooo, I walked out back with the owner and he showed me these VERY lightly used "store brand" tires (the mold nibs were still showing on the ROLLING SURFACE). So I let them put those on. They were sitting outside, though, so maybe that was a problem? Rubber looked quite nice and new, however.

Anyway, I've since had to put Falkens on the rear and will probably need to do the same on the fronts pretty soon. It's is hard to find local shops that have the size I need. Even Tire Rack has only a few choices. (I got the Falkens from Tire Rack.) I will look into finding a shop with the good balancing machine.

Highway Speed Vibration

Reply #8 – June 08, 2009, 01:40:53 PM

If you can't find 225/60R15 go with 235/60R15's. They're much more common. Mustangs, 83-86 Turbo Coupes and 84-88 XR7's were among the very few cars that used 225's. I had 235's on my '87 Sport. I would have put them on my 88 too, but I found a set of 225's for half price because the store was trying to get rid of them (they're hard to sell for the same reason they're hard to find - not many people want that size).

You've gotta ask yourself why those Big O tires were "lightly used". Were they a tire the store had already sold, and the customer was not happy with and returned them? That would be my guess. Few people would put a tire on a rim, then take it back off after only a few miles without a reason...

Highway Speed Vibration

Reply #9 – June 09, 2009, 10:17:56 AM

Yeah, that's true. I was kind of in a bind, though, as I had a 1500 mile round trip to take the next day, so I needed to get something on to replace the ones that were on the front and showing the belts in places!

I find that my digital speedo is about 2 mph slow with these supposed factory size 225s...I imagine I'd only make the problem worse with 235s. I'll have to check the tire size calculators and see if there's a combination (maybe in a 55 series) that'd work.

Highway Speed Vibration

Reply #10 – June 10, 2009, 12:23:54 AM

here ya go,,,,,quick and easy check............

drive car for a while or whatever you do
get out and feel the center of both front wheels

which one is hotter............?

now replace your caliper hoses and your warped rotors / pads
another thing, if the spindal is worn out , the inner bearings are just spooling on the spindal.
the spindal will have a worn section if the inner race of the bearing is spooling. I fixed mine with a small section of shim stock in between the inner race of the inner bearing and the spindal. The shim stock was obtained from a feeler guage set where i cut out a section of the .001 thin metal.

to verify rotors........
take off wheel
rotate rotor
listen for a off and on again rub.

how does the dash / wheel react when coming to a stop?

Highway Speed Vibration

Reply #11 – June 10, 2009, 10:43:44 AM

The rotors and brake pads are nearly new. I just repleced them last year. The wheel bearings were replaced at that time as well. Spindles *looked* fine, but I didn't have feeler guages nor calipers to check.

There is a bit of pulsating when I brake hard from highway speeds. Thus far, I've had 3 sets of rotors on the car, and the 2 that I've put on always seem to warp no matter how careful I am during the break in period. I don't know if it's the cheap steel used or what. Perhaps I need to buy rotors from places other than mainstream auto parts stores? Seems all I can find are rotors made in China or Mexico...

I guess my thought are not leaning toward this being mainly a brake-related issue since the vibration occurs as I'm just driving along at highway speeds NOT braking. It is possible the spindles could be worn, I would agree, however.

Highway Speed Vibration

Reply #12 – June 10, 2009, 05:56:21 PM

Control arm bushings?

Highway Speed Vibration

Reply #13 – June 10, 2009, 10:59:22 PM

Quote from: bike70ride;276826

The rotors and brake pads are nearly new. I just repleced them last year. The wheel bearings were replaced at that time as well. Spindles *looked* fine, but I didn't have feeler guages nor calipers to check.

There is a bit of pulsating when I brake hard from highway speeds. Thus far, I've had 3 sets of rotors on the car, and the 2 that I've put on always seem to warp no matter how careful I am during the break in period. I don't know if it's the cheap steel used or what. Perhaps I need to buy rotors from places other than mainstream auto parts stores? Seems all I can find are rotors made in China or Mexico...

I guess my thought are not leaning toward this being mainly a brake-related issue since the vibration occurs as I'm just driving along at highway speeds NOT braking. It is possible the spindles could be worn, I would agree, however.

ok,, i guess you didnt hear what i was saying.

At the metal crimp of the caliper hose, the hose breaks down on the inside and prevents fluid from leaking backwards back to the resivoir. this keeps a slight pressure on the rotor at all times and warps them. as the rotor spins through the pads it will shimmy the wheel.

Your symptom says it goes away and cycles so to speak.

for another good guess based on experience,
put the car in "N"
get under the car
move the drive shaft up and down near the YOKE where it enters the tail shaft housing.

if you have play there,,,,,,you just found your 3 dollar problem and fix.

Tailshaft bushing.

Its likely the bushing hasnt been replaced so if you find play there, go buy one and we will help you install it using Turbocoupe5.0's super secret method.

I think you have two problems myself, the cycle of vibration from the tailshaft as well as the root cause for warped calipers being the hoses to the calipers.

Highway Speed Vibration

Reply #14 – June 10, 2009, 11:14:58 PM

Quote from: bike70ride;276826

The wheel bearings were replaced at that time as well. Spindles *looked* fine, but I didn't have feeler guages nor calipers to check.

.

The only way I know of to check the spindal for the inner bearing is a visual inspection. Theres no way to verify the inner race of the inner bearing is not spooling on the spindal other than looking for the cookie crumb trail via marks it leaves behind on the spindal itself.

if you see an area up near where the inner race resides with marks or blemishes, that tells you you your spindals are worn.

root cause???????? someone did not go back in and resnug after a few miles. The tightness of the spindal nut may feel find during install but your suppose to come back and snug them once again as to insure the inner races of both bearings are not spining. They are suppose to stay stationary.

Here is my new habbit for bearings on fords............
I mark the side of the inner race with a marker and assemble the parts into the rotor,,minus the seal.
I insure both inner bearings mark i put on the side are both at the 12 o'clock location.

I put the nut on and snug,spin,snug,spin with the wheel on but no caliper.

I remove the wheel and then remove the spindal nut.
I remove the outter bearing washer and there i can see if the inner race on the outter bearing moved from 12 o'clock.
I gently slide the rotor off and the inner bearing should stay on the spindal. I look at the back side of the bearing sitting there on the spindal with a mirror. If the mark is at the 12oclock, then the inner race of the inner bearing did not spin on the spindal shaft.