Reading that font is more annoying than any vibration I have ever experienced! I can't even finish reading your post.

 

Service Writer at dealership is going to speak very kind and consoling to you.

Your easiest solution is do not drive at the "harmonic" speed. AVOID

t could be a 20.00 part $3000, 00 deep in the transmission. If this is even a probability your only hope is in a certified registered mail appeal to the factory rep that serves the dealership.

Have you changed wheels along w the tires. If a wheel (s) is out of round no matter what tire is installed you will reach that weird "harmonic" speed.

regards

 

Please change the font.

Sounds like you got a great score on the car.

Have them check or someone else check the wheel bearings. They're problematic on these cars, for some reason, and that will cause what you're experiencing.

The wheels would also be something to change just to rule them out.

 

for tire sixe use whats listed on the door tag. Most of the shops "speed" balance tires. A speed balance is basically a one shop deal and if its within half an ounce they say its fine. I had a similar problem but what I did after having them balanced and having the tires replaced with new ones at no cost is watched them balance them. The guy told me they were fine and I told him that he lied to me to get his manager. I stood right there while he zero balanced them. Zero balance means the tire is perfectly balanced. Then after they were zero balanced I had them check balance twice to be sure. Guess what, no more vibration!

 

From having so many tire changes on this car I have been able to see noticeable changes in the degree of vibration. Every time I would make a tire change it would get much better or much worse, but never completely going away. I have had two garages check the wheel bearings and tell me they were fine.
Before I bought the car I had them align the car because it had a slight pull to the left. Before they could align it they had to change the strut mounts and they paid for the strut mounts themselves, along with the alignment. It drove great after that, but I evidently didn't get it up to that certain speed for the vibration to kick in, so I bought the car.

Like I said, it's a 2002 with only around 20,000 miles. It was used before as a corporate lease car. From the place where I bought this car, I only got 3 months warranty. I only have another month left, that's why I'm trying to cure this problem quickly.
If they are going to let me change to Michelin's and help with the cost, that will make me happy. So I have a chance to put on any style I want, I just wanted to know what people recommended on this site as one that they were satisfied with.

Sorry about the font, it was copied and pasted from email. Didn't know you had a spell check, I'm new to the site.
I have to wait until Monday to do this change. I will let you know of the results.

 

Oh and thank you MashBill for making me feel so welcome to the site. Constructive criticism is always a good thing.

 

I meant no offense with my post and I certainly did not intend to make you feel unwelcome. Thanks for changing your font and welcome aboard! I think you will find that the contributors to this forum are friendly and very willing to help.

When I test drove my present DTS I noticed a slight vibration at 60 MPH. When I returned to the dealership, I informed them of the problem. They checked the tire balance and one was slightly off. They fixed it and I have never experienced the vibration since.

On my old Lincoln I had a vibration that turned out to be an out-of-round tire. An out-of-round tire can have perfect balance, but still cause a vibration when driving at speed. You might see if your tire dealer can look into that.

Bill

 

Since you have gone through so many tires, I think you can rule them out. Like C170B said, look at the wheels.

 

Sounds like you are in for a bit of stress. I've owned a 2002 DHS since new, have a 75k premium GMC warranty. I’ve had road vibration at 60-72mph absolute worst at 68mph since about 40K miles. Checking the wheels for out off round/warp (three shops) etc found nothing. Replacing the tires did nothing (two times). The problem got worse with every road trip. A local Cadillac repair center (not rated by GMC) - replaced the front bushings at 64K after the vibrations were so dangerous that I felt the vehicle was out of control on down-hill curves and braking -this did nothing. In and out several times the Cadi shop did nothing. Then, at an independent wheel shop I had the following at 70K- replacing the hubs did nothing, replacing a tie rod end (left side) did nothing, replacing warped brake rotors for the 3rd time (first at 20K second at 40K) combined with a frame alignment did nothing. At 71K I had the dealer tell me that the engine vibration was a broken motor mount. That did a little for the ride home, the vibration was still there. Then I noted that sitting in park, the engine has a harmonic vibration at 1400rpm and then re-immerges at 1700 through 2100 rpm - right at the cruising speeds or 60 to 72mph. I went back to the repair center and they agreed that there was harmonic vibrations but now I needed to pay for a $600-700 decarbonoization, which may or may not solve the problem. But no warranty work until doing that. Then, I went to a second Cadillac repair center (5 star), where they replaced another motor mount, told me that the harmonics was because the mounts were all of different stiffness (some new some worn in) and that was why the issues exist. Then they went into the whole wheel and tire song and I filled them in on all the history and they just held to the new mount stiffness explanation as no sensors show a problem. All the while they agreed that there were harmonics, but couldn't repair something like that.
So, new engine? New Transmission? New Car? Choices. In reading on-line I found that the Northstar is a super engine that is so good in general that bad ones are tossed out ad replaced - none are rebuilt.
So, I suggest that you check the vibrations in park and see what you get. Good luck.
Can you get your money back?

 

Ahh, the cry of the Deville owner! He sees the car... she is beautiful. Then
she nags him the rest of his days! I have a 2000 DHS with slight vibration.
Every Deville I have driven (three total) did this. Forget it and try to enjoy
the other nice things about the car. I bought mine knowing it did this
(even when test driving it). I must say that improper tire inflation seems
to make it worse. You should only be using the Michelin Symmetry brand as
these are the factory installed type.

 

Mine has Symmetrys. Had a slight vibration when I bought it 17K and had it road forced. Now has 19K and still has a very slight harmonic vibration. I can live with this one. My '02 SLS was bad enough that I put new tires on it at 22K. I don't ever remember cars being so sensative. I don't know what it is.

 

I think I have ever driven a car in my 15 years of driving that didn't have that speed range where there was a slight vibration. Maybe yours is a more serious problem but I have a 04 DeVille that has a 60 MPH vibration stops at 62 and when I drop down to 58.

 

Wow... this thread makes me happy and sad at the same time...

I have the dreaded 'vibration' and it seems like 1. It's a common problem, 2. there is little I can do about it. Damn shame.

 

Wow... this thread makes me happy and sad at the same time...

I have the dreaded 'vibration' and it seems like 1. It's a common problem, 2. there is little I can do about it. Damn shame.

Same here! I just bought an 00' DTS three weeks ago that had the vibration bad! I put a new set of Continentals on the car last week only to have the problem lessened, but not go away. My dad always drove Lincoln Town Cars, his last one was a 99'. I never remember them having these problems. I bought this Cadillac in order to have a cool car with a smooth ride. So far, I have been dissappointed.

 

I was hoping that when I changed my wheels and tires I would lose the vibration I had at 66mph.

Wishfull thinking. It is still there. I avoid 60 thru 66 like the plague.


BTW- I have used Michelins, Bridgestone, and now Pirelli's. All road force balanced, all had the same exact vibration.

 

Funny, I put "discount" Goodyear Allegras on my 90 Deville, and have no shudder problems anywhere from 60 miles to the electronically limited 118 mph.

 

HITMONEY; hows that thing in the rain with those tires? It must hydroplane like a bitch, no?

 

Nope, cuts thru like the Queen Mary. But I tell you, the best tire I have had on this car in the Florida wet were the the Michelin's.

 

Wasn't there a TSB on this? I think there was at least for the 2000 and 2001s. If memory serves the ultimate solution was to replace the lower control arms with a revised design.

EDIT: Found it (originally posted by Logan Diagnostic). There are 2 documents, one relates to replacing the lower control arm and the other relates to a different type of caliper bolt:


There have been some new control arms released. People who have had the arms replaced suggust it does not fix the problem. Here is the TSB:





Shake/Vibration in Steering Wheel, Floor, Seat at Highway Speeds on Smooth Roads (Diagnose/Balance Tires/Wheels)
1998-2004 Buick Park Avenue, Park Avenue Ultra

2000-2004 Buick LeSabre

1998-2004 Cadillac Seville (SLS, STS)

2000-2004 Cadillac DeVille (DTS only)

2001-2003 Oldsmobile Aurora

2000-2004 Pontiac Bonneville (17" Tires only)

This bulletin is being revised to add the 2004 model year and delete the screened tire program information for all tire manufacturers except for Continental General. Please discard Corporate Bulletin Number 00-03-10-007E (Section 03 - Suspension).

Condition
Some customers may comment on shaking/vibration in the steering wheel, floor or seat while driving at highway speeds (typically between 60-72 mph (96-115 km/h)) on smooth roads.

Cause
These specific vehicles may be sensitive to various rotating mass assemblies, especially if they are considered to be out-of-balance.

Correction
Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary.
Missing balance weights
Bent rim flange
Irregular tire wear
Incomplete bead seating
Tire irregularities
Mud/ice build-up in wheel
Stones in the tire tread
Set the tire pressure to 30 psi (205 kPa) COLD.
Road test the vehicle with the Electronic Vibration Analyzer (EVA) essential tool for a sufficient distance on a known, smooth road surface to duplicate the condition. Record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 10 miles (16 km) at 45 mph (72 km/h) or greater, in order to eliminate any possible tire flat-spotting.
If the road test indicates a shake/vibration still exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer. If any assembly calls for more than ¼ ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible.

Important
Some GM dealers may have a Hunter GSP9700 Road Force Balancer. This will simplify Step 5 by not requiring dial indicators. If a Hunter GSP9700 machine is available, it may also be used to measure the radial force of the tire/wheel assembly. A guideline here is 18 lbs or less.


While on the balancer, measure wheel runout. If radial or lateral runout exceeds .020 in (0.50 mm) for aluminum wheels (.030 in (0.76 mm) for steel wheels), replace the wheel.
After confirming wheel balance and wheel runout, if any changes were made, road test the vehicle again.
If the smooth road shake/vibration still exists:

Important
The completed worksheet must be attached to the hard copy of the repair order.


Record Radial Force Variation readings if you have access to Hunter GSP9700 Wheel Balance equipment. Use the worksheet found at the end of this bulletin to record the readings.
If one or more of the tires have RFV readings in excess of 18 lbs, match mount the tires to get below 18 lbs. Readings of 12 lbs. or less are preferable for critical customer concerns.
If the RFV can not be reduced to an acceptable level, replace the affected tire with one obtained locally.
The screened tire program is no longer in effect for Bridgestone/Firestone, Goodyear and Michelin. Low speed screened tires are available from Continental General only, and only for the Buick LeSabre.
Road test the vehicle to ensure the shake/vibration has been resolved.
Replace both lower control arms on vehicles built prior to the following VIN breakpoints. On Aurora, Bonneville, DeVille, Park Avenue, Park Avenue Ultra and Seville models, a newly developed hydro-bushing lower control arm with improved damping characteristics has been released. This control arm is not used on the LeSabre. The new lower control arms may provide an incremental improvement to the vehicle ride. Customers who have become "tuned in" to the shake condition may still feel some shake in the vehicle after the new lower control arms are installed. Refer to Lower Control Arm Replacement in SI (refer to the Parts Information table below for SI document ID numbers).

Important
THE CONTROL ARMS SHOULD ONLY BE INSTALLED ON VEHICLES IF, AFTER THE TIRE AND WHEEL DIAGNOSIS AND REPAIRS HAVE BEEN PERFORMED, THE VIBRATION CONDITION STILL EXISTS.


Model
VIN

Park Avenue
34175493

Seville (SLS, STS)
3U247643

DeVille (DTS only)
3U247644

Aurora
34175503

Bonneville
34175497


Parts Information
P/N
Description
SI Document

25746324
Lower Control Arm, Left (Aurora, Bonneville, DeVille, Park Avenue, Park Avenue Ultra, Seville)
Aurora -- 639351

Bonneville -- 657809

DeVille w/FE1, FE3 -- 724856

DeVille w/FE7 -- 724858

Park Avenue, Park Avenue Ultra -- 657760

Seville -- 539332

25746325
Lower Control Arm, Right (Aurora, Bonneville, DeVille, Park Avenue, Park Avenue Ultra, Seville)


Parts are currently available from GMSPO.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

E0901
High Speed Tire Shake
0.8 hr

Add
Measure Tire/Wheel Asm., Runout and Re-balance
1.3 hrs

Add
Replace Tire and/or Wheel - Each
0.2 hr

E3537
Arm Assembly, Front Control -- Replace
Use Published Labor Operation Time



Screened Tire Request Form (Bulletin 00-03-10-007F)

Fax Instructions:

Continental General : 888-847-3329





Here is the GM document 800385:


Support the brake caliper with heavy mechanic's wire, or equivalent, whenever it is separated from its mount and the hydraulic flexible brake hose is still connected. Failure to support the caliper in this manner will cause the flexible brake hose to bear the weight of the caliper, which may cause damage to the brake hose and in turn may cause a brake fluid leak.


Remove the brake caliper from the mounting bracket and support the brake caliper (2) with heavy mechanic's wire (1), or equivalent; do NOT disconnect the hydraulic brake flexible hose from the caliper. Refer to Brake Caliper Replacement - Front .



Remove the brake pads (2) from the brake caliper bracket.
Remove the brake pad retainers (1) from the brake caliper bracket.



Remove the brake caliper bracket. Refer to Brake Caliper Bracket Replacement - Front .
Mount the brake caliper bracket (1) in a vise.
Using a flat bladed tool carefully remove the pin bolt boots (2) from brake caliper bracket (1) and discard.



Remove the bushings (2) by carefully inserting a small screw driver into the brake caliper pin bolt bushing.
Rotate and pull the bushing outward to remove.

Important
Clean all parts in clean, denatured alcohol.
Dry with low pressure, non-lubricated, filtered air.

Inspect the brake caliper bracket for cracks. If cracked, replace bracket.
Installation Procedure





Important
When servicing a brake caliper equipped with the first design caliper hardware it will be replaced with the second design hardware. The second design hardware kit contains NIGLUBE lubricant and redesigned caliper pins. The second design hardware kit does not use bushings in the brake caliper mounting bores.


Using NIGLUBE provided in the hardware kit, lubricate the following:
Lubricate the bores (3)
Lubricate the inside of the pin boots (2)
Lubricate the new caliper pin bolts (4)
Install the new caliper pin boots (2) to the caliper mounting bracket.



Install the brake caliper bracket (3). Refer to Brake Caliper Bracket Replacement - Front .
Install the brake pad retainers (1) to the caliper bracket.
Install the brake pads (2) to the caliper bracket.
Remove the heavy mechanics wire.
Install the brake caliper. Refer to Brake Caliper Replacement - Front .

--------------------------------------------------------------------------------
Document ID# 800385


Jim