Front End Shudder - Part II
 

The wife's X5 has a front end "shudder" or shake when braking at highway speeds. I replaced the controls arms, which took care of most of the problem, but there's still a little shake left. What should I be looking at next - tension arms? ball joints?

For less than the price the dealership quoted to replace just the control arms($750), I can likely replace everything in the front suspension. :rolleyes:

sway end links may be a culprit... brake rotor deposits may be another...

Could be warped discs.

Yep in late summer, my front right disc got warped, and the car was shaking at higher speeds. I also thought it was the suspension, but it was in fact just the disc.

Diogenes...I have followed your "Shudder post" threads with close curiosity as I have been fighting the exact same situ for nearly the life of my '01 3.0. I'll save the litany of "fixes"/diagnoses; none have fooking worked. I had new front rotors and pads done by the Stlr 3 months and 4K miles ago, among other things, and it "seemed" ok for the first few times I hammered the brakes, but it quickly returned to the usual affliction...my point is I really doubt it is a "warpped disc" or "deposit" thing. I have no freaking idea what it is, but new rotors did nada for me. I am very curious to see how this thread goes...there have been a handlful of near identical wonderments over the past few years and I have never read of a real fix. I am beginning to think it is an unfixable or at least, an undiagnosible anomaly on some of our Xs.
GL,md

hey md... what tires you got? are they still in balance? are they in good shape? no cupping?

since you got pretty much all the hardware swapped out (brakes, control arms, etc), thats the last place i would look.. tires...

Thinkin' out of the box here...either of you guys (md or diogenes) had steering issues? Any steering components replaced?

JV

Hayku: orig Michey 18s, now with 50K...but, the shudder has been there since about Day 3. Tires are in very good shape, sidewall to sidewall, decent tread left, carefully rebalanced on a Hunter fancyazz machine, (the guy said wheel and tire were in v.good bal. originally as he "slightly" altered balance weights), etc., etc. It is a fooking mystery to me, but I do see this condition/phenomenom come up the Juke Box on occasion.

JV: No other steering issues. It is just a hard brake on @ high speed deal, and for me, an occas. noticeable wheel shimmy at less than high speeds. I have learned to live with it, though it remains disconcerting when me or V have to hammer the brakes on a high speed come down. It shudders and shakes, then...though repeating that action soon afterwards does not show the same condition. Ah, BeamERs, lol!
BR,md

hmmm.. i'm sure you had the pads changed at least once. was the wear on them even or was it at an angle?

if at an angle, i think you have excessive flex in your guide bolt bushings... that is, the rubber bushing that the 7mm bolts hold the caliper to the carrier are flexing to much... giving you a vibration under braking and uneven pad wear cuz they aren't stiff enough to hold the caliper flat/still.

I'm using "Army logic" here, bear with me. Is it happening no matter the weather or temperature? If it's not happening soon after you've hit the brakes at highway speeds, possibly it's the brake pads being "cold to the rotor" on that first application of the brake pedal, causing the pads or the rotor surface to not mate evenly, kinda like what Adam said.

JV