X3 out of balance wheels

[rocconi]

I had a little problem with 2 out of balance 15" X3 rims. The tire shop could not balance them properly so I did a little research. On the worst one there was .070" of radial runout on the inside edge of the rim (out of round) and .045" of axial runout (in and out). I figured that the radial runout was compensated for by the wheel weights and that the axial runout was the real problem. So I glued two .002" shims made from aluminum beer cans over one lug hole, one .002" shim over the 2 adjacent lug nut holes and nothing over the opposite hole. Contact cement worked very well for this since it is just a thin layer and it will not squish out of the joint. This reduced the axial runout to .025".

I rebalanced the tire and this fixed the problem almost 100%. It still has a very very slight shudder at 65MPH but it goes away above that.

I did have one slight difficulty when I moved the wheel to the rear. The drum was a slight bit warped to begin with and when I put the wheel on the drum the brakes pulsed quite a bit more. I rotated the wheel by 90 degrees on the drum and that fixed the problem. There is no pulsing at all. I think that the shims distort the drum just a tad and the out of round drum combined with the wheel shims made the condition worse.

Yes, I know that I you can send the wheels out to be trued up but that costs as much as purchasing a new wheel ($100 ea.). I looked on Tire Rack and they no longer carry wheels for the X3.

[TAK82]

does the tire have any heavy spot marks?, if so, match them to the valvestem

also, when mounting the wheel to the balancing machine, the amount of torque applied to the aluminum collar makes a different in balance,

if the wheel spins okay with no wobbles or hopping, i'm assuming the tire's belts are seperated,

[rocconi]

Thanks for the input but the tires seem fine. I measured the mounted tires and the radial runout on the surface of the tire was the same as the runout measured at the same point on the rim.

BTW those damm speed bumps do a tremendous amount of damage to aluminum wheels. The lower the profile of the tire the worse the damage.

[J0eFr0]

Originally Posted by rocconi

Thanks for the input but the tires seem fine. I measured the mounted tires and the radial runout on the surface of the tire was the same as the runout measured at the same point on the rim.

BTW those damm speed bumps do a tremendous amount of damage to aluminum wheels. The lower the profile of the tire the worse the damage.

what when your going 50 over them? yes

aluminum wheels are actually harder to bend than steel wheels because of the thickness.