96 Deville Droning Sound

[mharton]

Hi,

I just acquired my first Cadillac, a 96 Deville with 98,000 miles on it. It looks great and seems to run fine. I've got something going on, and I wonder if it sounds familiar to Cadillac experts.

It's a low frequency drone that I hear at low speeds - below 40 mph or so. It seems to be coming from the right front wheel, although the sound isn't easy to locate.

When I turn right, it increases in volume, and when I turn left, it goes away.

I've heard a bad wheel bearing do that before, but it made a metallic, scraping noise. This is just a drone sound that doesn't have any of that bad, metal-on-metal sound I got from my bad bearing (on a Ford.)

Thanks for any advice you can offer.

Marcus

[BodybyFisher]

You are correct, this is a bad hub bearing, I replaced both in my 96. Someone will chime in and help you with which one it is, I forget how to determine which one it is.

[CarlaValentine]

It's hard to tell by sound which one it is, since the sound tends to echo through most of the car. The method I have always used to determine which one it is is to jack the car up (one wheel at a time if need be). Then, facing the wheel, grab it on both sides and shake it back and forth. Do the same while grabbing the top and bottom. A bad wheel bearing would typically allow play in the wheel, at least it has in any case I have seen. If the bearing is extremely bad, you may even notice the offending wheel sits at a slight angle (cambered or toed in or out) with the car on the ground. I've only seen 2 cases that bad in my life...and by then I could feel it when driving.

[BodybyFisher]

Actually there is a definitive test

I forget how the test works, others know it

Its sort of if you turn right and you get the moan, its the left one and visa versa, but I am not sure of how it goes and why, its due to loading the bearing.

Someone will chime in, they dont always get loose, but they make noise, due to roughness/out of roundness on the rollers. Loading them, magnifies the noise

[Ranger]

Right turn loads the left bearing and it gets louder. Left turn loads the right bearing and unloads the left, so it will get quieter. Left bearing is your problem.

[BodybyFisher]

Right turn loads the left bearing and it gets louder. Left turn loads the right bearing and unloads the left, so it will get quieter. Left bearing is your problem.

Thanks Ranger, I can never remember this

[mharton]

- snip - Left bearing is your problem.

Thanks for the diagnosis. If the left is bad, could the right be far behind? Wonder if I should go ahead and replace both?

[BodybyFisher]

Well, I replaced both of mine, even though only one was bad. If you do this job yourself, it will be cheap enough to replace both, however, if you have the dealer do it, this job can be surprisingly expensive. The hub bearing ranges from $75 to $100

[mharton]

Thanks, I'll do it myself. I'm watching Ebay for a used FSM. Will get the FSM in hand before I start wrenching.

[BodybyFisher]

Thanks, I'll do it myself. I'm watching Ebay for a used FSM. Will get the FSM in hand before I start wrenching.

If you need help let us know, we have photos and can help with directions

[Ranger]

- snip - Left bearing is your problem.

Thanks for the diagnosis. If the left is bad, could the right be far behind? Wonder if I should go ahead and replace both?

I replaced the RF on my '92 at about 75K. Traded the car at 124K with the original LF bearing. Don't assume that if one went, the other is not far behind. If it ain't broke, don't fix it.

[mharton]

Ranger,

That's what I was hoping to hear. I'll be back if I need any coaching for the job. Saw a nice discussion of it in the tech tips forum.

Marcus