Dear Tom and Ray:
My car has almost 80,000 miles on it. It's a 2005 VW Jetta 1.8T GLI. It's been a great, reliable car, but I've been having a lot of trouble with the front-end suspension: I get a horrible wobble in the front end. It transmits through the steering wheel and feels like the wheels are wobbling very quickly, but only under braking. It is much worse under heavy braking, but it still exists even under light braking. I've replaced my tie rods after finding a little play in them, and I've checked my CV joints and axles, and they all looked good. The ball joints seem OK. The struts and strut mounts were replaced, and the car has brand-new tires that were balanced and aligned. When I replaced the tie rod, the shaking went away temporarily, but it's back worse than ever now. I'm getting really frustrated with this, and the car feels dangerous to drive. Any help would be appreciated. Thanks!
TOM: Brian, you've checked everything except the one thing that is most likely to be causing the problem.
RAY: Do you think he considers that good news or bad news? On the one hand, he's about to get the answer. But on the other hand, he's about to realize he just wasted several months and a bunch of money looking in all the wrong places.
TOM: I'm pretty sure he knows that already!
RAY: You almost certainly have warped brake discs, Brian. Your brake pads "grab" the disc from either side when you step on the brake. And if the disc is not perfectly smooth, the uneven spots will push back against the pads and make the brake pedal pulse, and/or make the steering wheel wobble.
TOM: And if we're right, it's not dangerous in the sense that a wheel is going to fall off soon. But it is dangerous in that it extends your stopping distance. And that can be serious, depending on the gross vehicle weight of the truck that's stopped in front of you.
RAY: So it should be fixed right away. And the other thing to check is your control-arm bushings. If you had a slightly warped disc and worn-out control-arm bushings, that slight pulsation you got from the disc could get magnified by a weak bushing and cause this kind of wobbling, too.
TOM: So now you know what to do, Brian: Replace the discs (I would not recommend trying to resurface them, in this case) and check those bushings.
RAY: And if that doesn't solve the problem, don't write back, because then we'll be out of ideas, too.