1998 S70 vibration through car when driving

Rocambolesque · Post by **Rocambolesque** » 25 Sep 2016, 20:25

My car has has a variation of this problem ever since I bought it. When driving at slow speeds, like 20-25 MPH, I can feel a clunk that seems to happen with every turn of one of the 4 wheels. At around 30-35 MPH, the clunk tones down but a slight humming noise can be heard. Around 60 MPH, it turns into a vibration (probably because the wheels are turning faster) and can be felt in my seat, the steering wheel and my feet resting on the floor. Usually, the problem is not so severe in the first minutes of driving. However, after a good 20 minutes, it gets worse. Note that the noise/vibrations don't change if I turn the steering wheel (like wheel bearings would do). Some days, the issue seems worse than other days.

What I did:
-I replaced both axles and it made no difference
-Inner tie rods were replaced, but didn't re-align the car after.
-Sway bar end links were replaced before me buying the car (they look new) a year ago
-Wheels don't seem to have any play when I grab them and pull/push on them. Bearings seemed good when I replaced the axles. No play, smooth operation
-Front brake rotors and pads are new

Known issues:
-The strut mounts make noises when turning the wheel while the car isn't moving
-The tires on the car are Sunny winters (probably not the best quality, most definetly noisy as well) that were on the car when I bought it. I have no idea if the wheels are out of balance or not (I don't even know how out of balance wheels feel...)

Any ideas?

Post by **kahl** » 26 Sep 2016, 06:12

I think you have several issues. I would first have the tires balanced. While they have the front right tire off have them inspect the engine mount on the front of the engine or right side of the car. Also while the front tires are off have the rubber bushings and ball joint in the control arms inspected. Plus outer tie rod.

I would have the car's alignment checked.

Rocambolesque · Post by **Rocambolesque** » 26 Sep 2016, 19:45

Thanks for your reply. How can I tell that the mount is bad? Is it easy to repair with the car on a lift? I checked the ball joints last time I had the wheels off and they were good. Same for outer tie rods. Alignment is off for sure since I changed the tie rods and only eyeballed the alignment after.

Post by **pvfjr** » 26 Sep 2016, 20:14

That sounds like a bad wheel bearing to me. You can jack up one wheel at a time, and lightly rest one hand on your coil spring while rotating the wheel with the other hand. The spring can help you pick up on vibrations that would be otherwise difficult to pinpoint when spinning the wheel slowly by hand. Alternatively, you can put a stethoscope on the back of each knuckle near the spindle while someone else spins the wheels.

I had an Impreza that sat for a long time once, and water pooled in the bearing race and pitted it out locally in only one spot. That bad spot in the race would make a light clunk with each revolution of the tire at low speeds, but turn into more of a groan at higher speeds. Turning corners seemed to have little affect on the noise. It was the least typical wheel bearing failure I've seen. There wasn't any axial or radial play in the bearing when inspected either. It's because the bearing never really wore out and got loose, it just developed a rough spot. The rough spot was hard to detect when the weight of the car wasn't bearing down on it. The vibration was light, but could be felt throughout the car. It sounds a lot like what you're describing.