wheel vibration/shimmy

I have an 03 Park Ave with only 48k miles. I bought it with Eagle LS tires on it. had them rebalanced and rotated. Still had a vibration at 60 - 70 MPH. I went and bought all new tires (Cooper CS4) and STILL have the vibration and shimmy at highway speeds. Anyone have ANY suggestion on how to get rid of this vibration????? THanks!

Some good thoughts in This Thread (http://www.automotiveforums.com/vbulletin/showthread.php?t=253267&highlight=VIBRATION)& This Thread (http://www.automotiveforums.com/vbulletin/showthread.php?t=885193&highlight=front+vibration)

I really need some help! I have gone through all the past threads that were linked to this post. I copied some of the suggestions and took them to the tire dealer. They have balanced the tires 3 times, aligned it twice, cross rotated the tires twice, and the darn thing STILL has a very distinct vibration at highway speeds. What now???? ANY further suggestions?:frown:

I really need some help! I have gone through all the past threads that were linked to this post. I copied some of the suggestions and took them to the tire dealer. They have balanced the tires 3 times, aligned it twice, cross rotated the tires twice, and the darn thing STILL has a very distinct vibration at highway speeds. What now???? ANY further suggestions?:frown:

This has been a much discussed issue with the Parks. Seems to affect various years (97-05) and both the Base and Ultra. Probably THE most popular suggestion was to get good Michelin tires; some were suggesting to get them road-force balanced.

I was chasing a vibration in a 99 Base. Put on Goodyear Tripletreds which helped a lot. Replaced the outer tie rods on both sides and a couple of alignments. Pretty good now, almost as good as the 97 Base I have. The 97 has a different control arm than the 99; I always wondered if the "improvement" was part of the problem.

EDIT...One mechanic I talked to said vibrations are almost always tire problems, so a good place to start. Also, put 1k on the tires to give them a chance to settle down.

Just seems like some Parks get this vibration problem. The question is...how much do you want to fiddle with it? Of course, when you get it right, the time/money may seem worth it.

On another note, reading with interest your upgrade to the Ultra. Have been wanting one with the Gran Touring option (this did not become standard on the Ultra until 2003). The Magnasteer has been standard on the 97-05 Ultra.

I have mounted more tires than I care to think of. especialy since I use an old Coats Tire Man from the 50s ( its manual but with a air cylinder bead breaker.)

Father complained about the same issue with his 04 or 05 Buick with the 16-inch rims. Removed rims, and tires, Balanced the naked rim on an old static Snap on aircraft style balancer (it was out by 1.25 ounces). Mounted the tire, again doing a static balance on the snap on. Moved the heavy side of the tire to the light side of the rim. Removed all weights. Then did a dynamic balance on an Old Bear 500. Replaced the tires on the car and it turned smooth as glass on a jack stand. Drove it down the road and there was no problems until 75. Checked the tires on the back and used the same procedure. Placed the ones with the least amount of weight on the front. END OF PROBLEM. I told my father the next time he needs tires, just bring it to me, and I will weld in wieght on the inside of those not so nice, but pritty 16 inch shinny rims of his.

Theory;

Besides the design of the front suspension sucks, this holds true for all cars.

The instantaneous speed of any tire as it touches the road is zero MPH. The instantaneous speed of the top of the tire is twice what you are driving at. That means that the heavy spot on the tire as well as the wheel weights are starting and stopping more than 11 times a second at 60 mph. THAT IS a heck of a lot of g forces tossing back and forth. Add to the mix that because the wheel weights are traveling in a smaller arc than the out side of the tire…… it is pulling a different g force as it spins around. All that means that you guna have problems. I am confident that if you have the tires spin balanced and there is very little weight, there will be no vibration if the tire is spinning at the same speed as the tire balncer spins the tire.

That is why you always place the tires with the big wheel weights on the back. and you can always find a sweat spot for a bounce on almost any tire with 1 ounce or more weight on it

name too long...

Good Information. Was wondering...do you find that Michelins (or any other brand) need less balancing? That was the point of people recommending them for the Park; more round. Would fit your theory and some Parks must be more sensitive to it.

Rims too...some purchased new rims to fix the vibration.

I'm no expert like the folks here, but when I had a vibration, and went to get tires, the guy at Suburban Tire told me I needed a tie rod end. With that and the tires, my '96 PA rides great...

Generally speaking, I have seen the cheap tires balance out with a total of less than 1/2 of an ounce, and some times less than 1/4. I have seen new Michelins with more than two ounces so brand does not always mater. On average I would say that for standard tires the Michelins, Goodyear, and other big brand names do better than things like Ameriglass. Cooper, etc. But I have seen a Kelly that came up with zero ounces. BF Goodrich from Walmart don’t seam to do as well as the BFs from a tire shop. (I think walley world may buy seconds. the same holds for guns, walley and k mart guns don’t look as good or shoot as well as gun shop guns)

For the best consistency of any tire, I have noticed that the higher the speed rating of any manufacturers tire, the better it is, compared to there run of the mill tire. That is right, the faster the tire was made to run, the more care they take in belt placing and tool alignment. That makes a more round finished product, and therefore uses fewer weights. There is also the matter of the tire holding its shape better at speed and therefore maintains the balance over a wider range.
(That is just my hypothesis but it turns into a theory on the balancer)

No one ever said that a wheel is round but generally speaking, steel wheels are all of by less than <1/4 ounce. Billet aluminum wheels are also close, and usually come up 0. Cast aluminum wheels can be off by ¼ or more. But you have to remember that all things being =, an aluminum wheel weighs more than its steel counterpart. Yes that is correct steel wheels weigh less than standard aluminum wheels of the exact same size. That means any inconsistency makes less of a difference on the aluminum wheel. There is also the matter of aluminum flexing and they’re for isolating tire rotation from the suspension. That is why aluminum generally run smoother than steel.

My 70-year-old father use to drive Sears nuts. (Back in the day they honored the satisfaction guarantee.) He would return Michelins the entire time saying that they where “lumpy”. And yes they where. Personally I think that Michelin spends a ton of money on advertisement and some one has to pay for that...., that would be you. People are convinced that you do get what you pay for, and that is not always true, some times you get a baby sitting in a tire and are told, “you have a lot riding on your tires”. Personally the only car that I have with good tires on it is; My 88 royal because I use it for family trips. On that car I am running Yokohama V rated radials, those are smooth, I mean smooth. But they are low profile so they do transmit a bunch of road feel to the car.

Last but not least I would just like to make it clear that I am not a mechanical engineer, or a tire guy. I just have some interesting toys around the house and people found out that even when the local tire shops say… mount and balance is free…. They will nock of 12 to 20 dollars if you cash and carry the tires…… I do it all for 7 bucks each, from time to time. After disposing of the old tires that comes to getting paid 88$/h. Now that I have thought about the hourly rate….. I wonder if I had some sort of subconscious computations involved in charging 7 dollars each. Because it comes out to 88$/h and car is moving at 88 feet/second when traveling @t 60mph.

Thanks...great post.

Again, I think we can say that some Parks are just more sensitive to these inconsistencies. May be the suspension design or whatever, but certainly has caused frustrations.

I seem to recall Buick issued a service bulletin on the issue, and guess what, they recommended putting Michelins on. Hit or miss attempt.

Anyways, the Park is out of production :frown:, have not followed the Lacrosse or Lucerne closely enough to know how they are doing.

With these new govt. regs on MPG I'm afraid the larger cars will disappear and we will get the smaller/lighter cars. Not good news for us in MT with some of the weather and two-lane roads we drive on. Hope that safety does not get completely trumped by this perceived need to reduce demand for oil. Some people say the oil shortage issue is bogus. But this also ties to environment issues and global warming. :runaround:

Well let me say something about the almighty gov regs. Maybe you did not know this: when the US enacted all those café standards back in the late 70s early 80s. They stated that US made cars must make X miles per gallon on a production basis. Ford made the engines and transmissions in Mexico so the Lincoln Town car, the crown vick, and the Mustang where technically an imported car. That meant they did not count on the Lineup average for MPG. You see these new regulations is just another hoodwinked attempt at lowering the US standard of living, exporting jobs, and raising the rest of the worlds standard of living. ( it is funny when compaired to how well The POTUS has treated his aint, his brother, and now the children of D.C. with the deletion of the credits to private and charter schools.)
Large cars will always be available in the US. Unfortunately they are going to price them out of the average persons price range. If you think that a Congressmen is going to drive around in some sort of electric clown car with no A/C no Heat, and a top speed of 70MPH you have another thing coming. Hell it must take at least 4 MPG off the total mpg just to haul around all the armor and bulletproof glass on Falloasies car. Ever notice that she flies around in a Gulf Stream 6 or 5 at our expense.
But I guess that as long as people have cheap Food, porn, and beer. They won’t notice. In some ways I thank the gov for making all these changes over the years because I have found ways around and to take advantage of the welfare state, and all of these silly rules. Back in the early 90s I was making around 70/75 K per year. Now I have a family, I have not had a job/ job since 1997, and I have a much better standard of living.
Now that that Dork that reads off the teleprompter and the Dems have seceded to give bonuses to states for increasing their welfare roles…….. I guess it is time to expand my current six-slum rental unit empire to something like 20. You see after the feds passed the current legislation that rewards states for expanding the welfare roles. The amount that the state will pay for a dump is going to break the glass sealing. Right now is the time to buy what is referred to as a handy man special.
I am going to the auction and BUY BUY BUY…..


Good luck with your car

PS:
know what you do when a section 8, or welfair person breaks a window........... Take the window out with plywood on the out side..... and drywall on the inside. Some times they dont get it on the first try....... but they get oit n the second.......
When they call the Code enforcment people... they go... So?

You see these new regulations is just another hoodwinked attempt at lowering the US standard of living, exporting jobs, and raising the rest of the worlds standard of living. ( it is funny when compaired to how well The POTUS has treated his aint, his brother, and now the children of D.C. with the deletion of the credits to private and charter schools.)
Large cars will always be available in the US. Unfortunately they are going to price them out of the average persons price range. If you think that a Congressmen is going to drive around in some sort of electric clown car with no A/C no Heat, and a top speed of 70MPH you have another thing coming. Hell it must take at least 4 MPG off the total mpg just to haul around all the armor and bulletproof glass on Falloasies car. Ever notice that she flies around in a Gulf Stream 6 or 5 at our expense.
But I guess that as long as people have cheap Food, porn, and beer. They won’t notice. In some ways I thank the gov for making all these changes over the years because I have found ways around and to take advantage of the welfare state, and all of these silly rules. Back in the early 90s I was making around 70/75 K per year. Now I have a family, I have not had a job/ job since 1997, and I have a much better standard of living.
Now that that Dork that reads off the teleprompter and the Dems have seceded to give bonuses to states for increasing their welfare roles…….. I guess it is time to expand my current six-slum rental unit empire to something like 20. You see after the feds passed the current legislation that rewards states for expanding the welfare roles. The amount that the state will pay for a dump is going to break the glass sealing. Right now is the time to buy what is referred to as a handy man special.
I am going to the auction and BUY BUY BUY….. :nono: AF does have a Politics, Investments & Current Affairs (http://www.automotiveforums.com/vbulletin/forumdisplay.php?f=980) forum to vent your political likes/dislikes, but this is a technical forum. Please try to keep your post on the subject! Thanks

I bought top of the line Cooper tires - Cooper CS4 which came HIGHLY recommeded by a few people on the forum and at some of the tire dealers I researched. The tires ride well, and are very quiet, it is just the vibration. Wheel force balancing showed 3 of the 4 were so far out of round that they would not be possible to balance. Rims checked fine. Back to the tires store. I truly wish I had waited and looked for a base PA instead of the Ultra. I am one of thos ethat like that boulevard ride and float that the base PA gives. The Ultra with the GTS is DEFINITELY NOT that kind of ride! Getting tired of dumping $$ and energy into a car that sounds like it might not EVER drive correctly. sad....................

well................. this is the end of this thread. They FINALLY got the balance right. Road Force balancing is the ONLY way to go...................I had it road forced balanced, and they found 3 of the 4 Cooper CS4 tires were NOT able to be balanced they were so far out of round. The highest number you can have on this is a 15 - these were all in the 40 - 50 range. I went to the tire dealer, he gave me 3 more CS4's - unmounted, and I took them back to the dealer. They mounted and balanced them with only ONE tire having to be reindexed and VIOLA! The car is totally vibrationless!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! You can not believe the difference this makes in your car. I highly recommend doing this before people start dumping $$$$$ into needless front end repairs. Thanks to all of you that offered help and suggestions!

The instantaneous speed of any tire as it touches the road is zero MPH. The instantaneous speed of the top of the tire is twice what you are driving at. That means that the heavy spot on the tire as well as the wheel weights are starting and stopping more than 11 times a second at 60 mph. THAT IS a heck of a lot of g forces tossing back and forth. ]

The forces on the tire are relative only to the axis about which they are rotating.

well................. this is the end of this thread. They FINALLY got the balance right. Road Force balancing is the ONLY way to go...................I had it road forced balanced, and they found 3 of the 4 Cooper CS4 tires were NOT able to be balanced they were so far out of round. The highest number you can have on this is a 15 - these were all in the 40 - 50 range. I went to the tire dealer, he gave me 3 more CS4's - unmounted, and I took them back to the dealer. They mounted and balanced them with only ONE tire having to be reindexed and VIOLA! The car is totally vibrationless!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! You can not believe the difference this makes in your car. I highly recommend doing this before people start dumping $$$$$ into needless front end repairs. Thanks to all of you that offered help and suggestions!

I didn't see your thread earlier but road force balancing with a tech doing it who's knowledgeable is the only way to do tires on these cars.

The tires from Michelin tend to roll round when being compressed under load. Taht's why the TSB someone mentioned had the dealers replacing the original tires on certain GM cars with Michelins. I bought my 03 leSabre because it had Michelins on it from the factory.

While other tires roll round when no weight is on them, when spun on the balancer with force on them, they don't roll round.

A force variation of 12 and less is really good. On my originals one was about 12 and others were single digits after the dealer road force balanced them using the precision setting, not the "close is good enough" setting.

Also the problem with the wheels and tires transmitting some vibrations is from the Riviera and Aurora era where the chassis was really stiffened. The lighter suspension parts on these cars means less weight for a wheel to move up and down; the heavier parts kept the out-of-balance movement from being transmitted as much. But add the alloy A-arms and stiff chassis and vibrations became a problem.

The last word, is have the car perfectly aligned to the specifications front AND back now that you have 4 good tires. Slight misalignment made my car have a slight vibration which the dealer rebalanced for, drove a couple of times with vibration analysis device attached, and then realignment did it.

imidazol97...glad you are still around...the info I spouted was mostly gleaned from your responses helping PA owners (here and other).

Of course hotz28 is the anchor...answering post after post when everyone else seems to have disappeared or has not the knowledge.