Why does your 2000 Buick Century wobble on acceleration?

Answer 1

If the wobble occurs ONLY under acceleration, as this member's question implies, it is most likely a worn constant velocity (CV) joint. To check for this it will be easiest if you raise the front end of your car on jack stands.

PLACING CAR ON STANDS: Park the car on a concrete slab, apply the parking brake, chock both rear wheels and then use a heavy-duty trolley jack to raise her front end and set her down on jack stands one side at a time. The factory jack points for the 1996-2005, Buick W-type body were flimsy except when the emergency jack was used. So, to avoid cosmetic damage to a beautiful car, don't use the factory points (just behind the front rocker panels). Instead, use the forward end of the sub frame members, which are clearly visible running longitudinally about 10-inches inboard. When she's securely on the stands, wheel your jack under the steel member that crosses beheath the heat exchanger and leave it there to catch the weight in the event your stands fail. You might damage your radiator but at least you'll be alive to pay the repair bill!

VISUAL INSPECTION: Begin with a visual inspection of the CV joint boots. There are two on each side. The inner CV joints permit the drive shaft to move in a vertical arc. The outer ones permit steering. Turn the steering wheel as far as it will go away from the side you want to check first. Shine your shop light into the wheel well. Turn the wheel slowly one revolution with your hand while examining the rubber boot for cracks or tears. You have to kneed and push at the rubber with the fingers of one hand to get a good look inside the pleating. If there have been any breeches to this protective envelope over the last few hundred miles of driving, dirt will have gotten in, the joint will be junk and you should replace it. I keep my boots lubed with Permatex silicone spray to keep the road acids from degrading the rubber prematurely.

PALPATION: CV joints will wear out eventually, even if the boots stay intact. They started to show signs of wear on my Century at about 85,000 miles but the need to replace them remained a matter of personal taste for the next 15,000 miles. To check for invisible damage beneath the boot, wash your hands and put a clean blanket over the driver's seat before climbing into the car (still on the stands). Put the transmission in park. Now climb out and give each wheel a hearty twist with both arms, back and forth. There will be some play, even in a new drivetrain, but there should be no 'bump' or 'rattle' sensation on the reversal of your twisting motion. If you feel any 'bumps' or 'rattles', you need at least one new joint. To tell which CV joint (inside or outside) needs replacement will require some disassembly. Personally, I like to just go ahead and replace all four at the same time. They're going to last you another 100,000 miles, so why not?