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Vibration

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sailing_glayva

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I am getting some vibration when approching 55 mph. I have new tires and the dealer has re-balanced the wheels. The vibration is comming from the back (I think?) as the steering doesn't shake in my hands. The dealer said my rims were wobbling a little but did not think it should be a big problem.

Is it possible the brake drums are out of balance? Does anyone think an on-the-car balance might solve this problem?

any Comments?

tks Brian
 
There is something about how the driveshaft goes together!! It is very important, but I am drawing a blank!!
thirsty.gif
CHUCK!!!! HELP!!!
 
Sailing:

Any wheel wobble is not right, if they are wire wheels get them tuned, if the wheels are aluminum or steel they can be repaired, if not better find new or good used. Check driveshaft for vibration and balance. If vibe is felt in the seat, definitely rear.

Larry
 
Thanks Larry and Lloyd

What kind of place can true up steel wheels ?

How would I go about checking the balance of the drive shaft ? I just did a little research and read when removing the propeller shaft to reassemble the flanges at the same spot to maintain the fine balance of shaft.

I did not have the shaft off the car. This is why I am questioning the balance of the brake drums and the Idea of an on the car balance. It did not have so much vibration at the same rpm before changing the tires.

Thanks Brian
 
Sometimes weights are welded to the drive shaft and they can come loose and fall off. Check to see if there are any barespots on the driveshaft.
 
Just because they said they're balanced doesn't mean they're not going to generate vibration (or indeed that they've really been accurately balanced). Unless they used a roadforce-capable balancing system to mount the tires to match the rims then you CAN have an in-balance condition with a wobble that will inevitably cause vibration.

Check around for shop equipped and properly trained to use a Hunter Engineering GSP9700 balancing system (see https://128.242.141.111/ for a list of shops and more information). The GSP9700 works by mounting the tires so the wheel/tire system creates a smooth rolling unit. It also uses applied force to hunt for soft/stiff parts of the tire so that the final results give you a constant smooth ride.

Once you've gone through the process of remounting the tires and balancing them properly with this machine the operator should be able to tell you whether or not the tires are good, whether the rims have excessive runout.

I was introduced to this system a couple of years ago when a friend of mine changed to a new set of Goodyear tires on his truck and had nothing but trouble. After going to three shops for rebalancing he was ready to ditch the new tires - then found a GSP9700-equipped shop. That shop went through the whole process and found that two of the new tires were out of spec, replaced them for free (they were a Goodyear dealer), then mounted and balanced all four with the GSP9700. It made the difference between annoying vibration and unbelievably smooth.
 
Thanks Scott

Great tip!

I have looked at the GSP9700 on the Hunter site and definitely going to try it. It makes sense.

From here I will know the real story about the my wheels and tires and hopefully be running smooth again.

Brian
 
check your u-joints
 
Here is my final result for all of your information.

I took my two rear wheels to Parkers Auto Care in Ottawa Ontario. They had the GSP9700 system that Scott was talking about.

They found both tires as mounted had excessive amounts of road force. The first had 42 lbs and they reduced it to 2 lbs. The second wheel had 64 lbs road force and they told me the rim runout indicated a defective rim. They did the match mount anyway and reduced the excessive road force to 30lbs.

I mounted the two wheels today and the car was running quite smooth I am satisfied. I can drive again! I will be looking for 1 rostyle rim to replace the defective one in the future but I feel no pressure to do it right away. I will get the two front wheels checked on the gsp9700 also.

Some important observations when balancing tires with ROSTYLE rims.

The initial installer mounted the wheels on his balance machine with the center hub. Like any other wheels. Well the rostyle wheels are cone shaped and the hub is at the end of this cone. The hub is offset from the usual mounting holes on the rim. This system of mounting is, I believe ineffective with a dynamic balance because the wheel is mounted off plane (horizontal) to the way it normally mounts on the car. The dynamic balance addresses vertical and horizontal planes.

I noticed the GSP9700 technican took great care when mounting the rims on his equipment. He used a studded flange to simulate a correct mounting plane as the wheels would normally be on the car. And he cleaned the rims to ensure good contact with the flange.

In short, at least find a dealer with the proper flange mounts for your Rostyle wheels.

Thanks for all of your input and hope this thread keeps things smooth for you.

Brian
 
Great to hear there was a difference Brian! The GSP9700 also has some kind of special centering system to ensure everything is trued before going on the machine (at least that's what they claim). You can imagine that it's not only important for balancing, but also to measure the runout and roadforce.

You've found two of the really neat features of the system too - you know you have a bad wheel with some hard factual information without much effort, and you have some real data on the quality of your wheel/tire systems on the car.

--Scott
 
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