Rear Wheel Horizontal Vibration Solved!

[snkpkp]

few weeks ago I purchased my used 2004 X5 4.4i with 18" Sport Wheels,
I reported in other threads that I felt my car was bouncing in an odd manner not the sport package type suspension issue, sort of a horizontal back and fourth in low speed from 20-40 MPH. So I take to BMW, they check and say everything is FINE and thats just the vehicle characteristics. Then I take it to a independent wheel and tyre specialist and they changed two rear tires first and did an alignment both front and rear and adjusted camber settings according to BMW specification and we did a test drive and not to my surprise the dancing and horizontal vibration in low speed is gone and not just that , the whole ride seems so much better. Later I changed the remaining front tires, and balanced them. I will post the change in camber and alignment setting they made. Just loving the ride more now.....

[JT///MC]

sounds like the rear tires were out of round and unbalanced. pretty simple fix!

[snkpkp]

These are the settings changed in the X5 wheel alignment and rear camber. I have no Idea what these numbers mean, but I feel like I was missing a whole lot of good ride comfort.

Settings :

FRONT AXLE

BEFORE AFTER

Total Toe +3.7mm +2.2mm
Partial Toe L +0.6mm +1.1mm
Partial Toe R +3.1mm +1.1mm

REAR AXLE

BEFORE AFTER
Total Toe -4.3mm +2.4mm
Partial Toe L -2.1mm +1.2mm
Partial Toe R -2.1mm +1.2mm

Camber L -02*40' -02*07'
Camber R -02*06' -02*03'

* symbol is printed as degree,but couldnt find degree symbol on the keyboard.

[JCL]

You say they changed two rear tires. I assume that means they replaced them, and didn't just swap them side to side.

If the tire reinforcing belts fail, the tires will not be running true, and that can evidence itself as feeling as though the vehicle is moving back and forth side to side, at low speeds. The balancing is necessary when you change tires, but it doesn't sound like it had to do with your symptoms, since the problem evidenced itself at relatively low speeds.

The camber (how much the tires lean inwards at the top) hasn't been changed much from the printout.

On the rear axle, the toe-in (how much the tires point inwards, like when you do a snowplow on skis) was actually toe-out before adjustment, since it was negative. That is the only significant alignment number that they appear to have changed.

Looks like you are good to go.

[snkpkp]

Originally Posted by JCL

You say they changed two rear tires. I assume that means they replaced them, and didn't just swap them side to side.

If the tire reinforcing belts fail, the tires will not be running true, and that can evidence itself as feeling as though the vehicle is moving back and forth side to side, at low speeds. The balancing is necessary when you change tires, but it doesn't sound like it had to do with your symptoms, since the problem evidenced itself at relatively low speeds.

The camber (how much the tires lean inwards at the top) hasn't been changed much from the printout.

On the rear axle, the toe-in (how much the tires point inwards, like when you do a snowplow on skis) was actually toe-out before adjustment, since it was negative. That is the only significant alignment number that they appear to have changed.

Looks like you are good to go.

yep they installed new tires, and thanks for your explanation.