Hello All,

1999 Bonneville SLE, 137k, pure stock...New Pads/rotors, new tires recently...

Here is the problem - when traveling 55 mph or more, tracking straight I'm experiencing what I can only describe as a rapid flopping or knocking noise from, I believe, the driver side of the front end. When I turn the wheel slightly to the right the noise gets louder (I can also feel this in the gas pedal and the floor boards) - when I turn the wheel slightly to the left, the noise completely goes away until the wheel returns to center when I begin to hear and feel it again. Seems to be worse in warmer weather, and it is not noticeable at lower speeds. I have had 3 techs (including a former GM tech) analyze the front end and all of them have told me they cant find anything wrong.

This is getting really frustrating because there is something definitely wrong. Could this be a bad CV joint and/or a hub assembly? All parts and linkages, according to the techs, are tight....

Any suggestions are greatly appreciated.....Thanks in advance!!

Could be a bad left wheel hub.

Check you CV boots the Half shafts could be going.

Thanks Gentlemen,

I figure that it is either a hub or cv that is going out. Just hate to throw $$$ at the car withour being sure. I probably need to have the tech take a ride with me so I can show him directly what the problem is. I don't think just shaking down the front end on the lift is going to do it.

That might show if the CV is going out, but not the hub. I suspect the hub because you said it'* louder when you turn. This puts more pressure on the outside hub. I just replaced a hub Sunday, it'* not a very hard job.

if i were you i would jack up the front end grab the strut spring and spin the wheel you will be able to feel a bad hub in the spring

The one I replaced Sunday had nothing I could feel by spinning or wiggling the wheel. It wasn't until I have it off the car that I could see the problem. It was very hard to turn, the bearing had gone tight. It was much louder when turning.

What is strange about this is that it feels loose as opposed to groaning or grinding. At lower speeds everything seems fine - but over 55 I get that repetitive knocking or slapping sound and feel. Also, I should have mentioned that if I am in a parking lot and drive into a shallow pot hole it feels like something is moving around on that same wheel - almost like a cv joint is loose within one of the boots.

I may just bite the bullet and do the half shaft and hub and hopefully be done with it. I may have multiple problems contributing to what I am experiencing. Considering the mileage of 137k and I don't know the history of the car before 108k. Also, I recently put new quick struts in as well.

Let me know what happens I have a 1992 with 110,000 with the same issue.

Hi Jake,

I had Pep Boys replace the hub and the cv half shaft on the driver side. The tech told me that both items didn't seem too bad individually, but he felt they weren't 100%. Problem solved; smooth as glass and no noise or thumping whatsoever. About $350 total for the job. Anyone that has the proper setup to do it themselves will save about 150.00 in labor. Basically both parts are bolt on.