Car question where does it belong?

[tw]

Originally Posted by footfootfoot

CAr ??mystery?? update:

Oddly enough after the road force balancing, the wobble was worse.

What manufacturer and model tires? Why do you (he) know the tires are not defective? How do you know shocks are good (since struts must never fail)? Bent axle on a front wheel drive car? Where did that come from?

Scalloping tires are most often due to bad struts.

What kind of noise? Does the steering wheels shift right-left or just the car goes up and down?

If not this and not that, they the reason why must also be provided. Based upon what was posted, everything remains on the list of suspects because 'reasons why' are not provided.

Of course, there is always Car Talk on PBS. I suspect they would have fun with scallops.

[footfootfoot]

Originally Posted by tw

What manufacturer and model tires? Why do you (he) know the tires are not defective? How do you know shocks are good (since struts must never fail)? Bent axle on a front wheel drive car? Where did that come from?

Scalloping tires are most often due to bad struts.

What kind of noise? Does the steering wheels shift right-left or just the car goes up and down?

If not this and not that, they the reason why must also be provided. Based upon what was posted, everything remains on the list of suspects because 'reasons why' are not provided.

Of course, there is always Car Talk on PBS. I suspect they would have fun with scallops.

The current tires are Dunlop signature all season radials. While the problem started when I got these tires at around 84k miles, it was likely coincidental since the problem remained when we swapped to snows which were Nokian hakkapeliita (sp?) We don't know the tires are not defective, they may be, but it seems odd that all four would be bad. We had a road force balance doen and while the machine did not indicate a tire or rim problem, the tech said he still suspected the tires.

I have no idea if the shocks are still good, the dealership mech said the front end looked good to him, would he be able to tell if the shocks/struts were bad by driving and inspecting the vehicle? Since I assume they are consumable parts and not part of the drive train, I imagine he'd be happy to sell them to me. What are the symptoms of bad shocks/struts? (I've heard scalloping tires, but no one thought that was the case with my tires. Who knows?)

Bent axle? that was BrianR.
Noise? who said anything about noise? There is no noise, just a vibration which has now extended from 20-30mph to 20-45mph. The steering wheel judders back and forth in a small arc. The car doesn't bounce like a car with bad shocks does. It handles nicely with the exception of the vibration.

A new development is that when you come to a stop and make a left turn after complete the turn and you straighten out the vibration is noticibly lessened. After making a right turn it is noticibly worse.

We'll see what happens tomoorow.

As bullitt points out "Once you lose traction..." I find that point comes a little later with good snows. Then again, you never know how fast you can corner until you wipe out.

[tw]

Originally Posted by footfootfoot

A new development is that when you come to a stop and make a left turn after complete the turn and you straighten out the vibration is noticibly lessened. After making a right turn it is noticibly worse.

That symptom is characteristic of improperly seated and now failing bearings - as but one example. A sharp turn seats the bearing temporarily in a fixed position.

Worn CV joints cause noise, especially during a turn. Noise is the usual symptom; not the only one.

Tech suspected tires even after balancing them? Why? What were his reasons or was he just wildly speculating?

Balancing tires would not affect these reasons for failures. One, a tread that is not straight and true all the way around the tire (which is determined with a pencil carefully held against the tire as the tire is rotated). Two, a hard spot (lump) beneath the tread typically created in manufacturing such as a belt that was not flat, how the end of a belt terminated (ie folded over), or maybe the belt was skewed during assembly. Of course, this is not likely also with a second set of tires. (Possible with all tires from one defective batch.) Three, somehow the tire is not mounting flat on the disc (wheel) assembly (which is obvious by rotating the entire wheel assembly while holding a pencil at the tread).

When were brakes and other suspension work performed? Was wheel alignment performed? If alignment was necessary on a Hyundai, then what defective part was replaced that caused misalignment?

Struts - driving will only detect struts that are so bad as to have been long and obviously defective (ie long ago caused scalloping tires). The traditional way to know a defective strut (or shock absorber) long before any driver knows it: fluid stains where a stainless steel rod enters the strut/shock body. A defective shock is rarely apparent to a driver even when adjacent cars can even see that tire bouncing excessively.

Struts should never fail on any car. Yes they fail just wiper motors burn out and rear seats collapse. Strut failure is that rare when the car is properly designed and not run off road at high speeds.

If previous tires were scalloped, then what was fixed / changed to eliminate that suspension problem? Scalloping is typically not a tire problem; typically a symptom of suspension defect.

Also possible are worn bushings or other suspension parts that sway only when underway and under load. For example, bad ball joints may be not obvious due to internal spring loading. Forces necessary to identify an excessively worn ball joint can involve a crow bar and full body muscle while the other mechanic feels or measures for fractional ball joint movement. How to inspect your ball joints? Consult the shop manual. It can vary with vehicles.

Of course, any broken ball joint rubber boot would also be obvious.

Another less useful symptom. How fast must a left and right turn be to cause tire squealing?

Bent axle - there is no axle on engineer designed cars. However a severely worn CV joint wobbling is the performance equivalent of a bent axle. Yes, the spline that includes bearings can be bent. But then wheel alignment would have detected that bent part. Again, don't align to bent parts as too many mechanics do. An alignment problem is a message to a good mechanic - find and replace that bent part.

Steering should be a rack and pinion system. A worn rack means the toe in would change / vibrate as both tires vibrate in and out simultaneously - not held in parallel by a worn steering gear or ball joints on that steering gear.

Back to point number one. Notice the large number of possible reasons for vibration. Any mechanic that says "it is this" or "it could not be that" without supporting reasons why has said nothing useful.

Scalloping is the symptom of bad struts / shocks which are quickly identified by inspection. CV joint failure is often indicated by noise and often created because a CV boot has / had failed. Most likely reason for a wandering and therefore vibrating steering is failures in the wheel bearing, bushings, or ball joint (on suspension or steering).

Back to important facts still not provided. Was any wheel alignment performed? When were brakes replaced, by who, and how? Were rotors turned down while on the vehicle or in the machine shop?

The best mechanics would be asking these questions and consider all those items. Of course, a mechanic who only works on Hyundais would also have experience with what parts tend to fail more often. Asking damning questions and providing detailed information (as if you know rather than from a list provided by another) may get the shop manager to assign your car to his better man.

Good luck and report back.