dlazrael

So, while on my way to work, I discovered the sounds below. I will try to describe the best I can because I cannot get something to record the sound where the it's located.

(With window up or down)
While braking, coming to the stop (the last 5,mph or so of the break) there is a grating almost grinding noise, this sounds like its coming from BOTH sides, but it is hard to judge. It's definately driver's side at the least.

While braking, the wheel DOESNT shimmy (like it did before when my rotors were warped)
There IS a slight wheel shimmy at 65-75mph but feels like that may be more or less a wheel balance issue. tire inflations are all good and normal. Alignment is still good, car doesnt pull to either side.

I haven't noticed a loss of braking power, but then I don't tend to slam hard on the brakes unless absolutely required... I don't like buying new pads every 10,000 miles!

(window down)

More disturbingly, while basically coasting through base to get to the firehouse (surrounded by 5+ storied buildings) there is a wierd rattle, almost like something is vibrating against the brake dust shield, but only when turning and under power, generally only at low speeds (below 20 mph).

Now for my rule outs:
Power Steering - no noises at standstill, no power loss, full range of motion on wheel and turn radius
Brakes - reverse up to 25mph and hard on brakes does not reproduce the noise. however any speed in forward motion causes the grating grinding noise. I just picked up a digital micrometer and when i get a chance I plan on pulling he tires and measuring the rotors to see if they may have warped. (They're at least under warranty with advance, so I can exchange them if thats the issue)
Alignment - normal
Suspension bolts - All appear tight, friday is the first day I can get a lift to go check all the torques and ensure they are good
Visual - nothing loose hanging or bouncing around that I noticed. There is even and normal wear on the rotors, no obvious gouging or glazing, The brake dust shield is tight and not against the rotor when at rest....

It's all just wierd and I'm not sure where to go. I haven't slammed any bumps lately, and while I do some "spirited" backroad driving, I'm not 100% sure this is warped rotors... ideas are welcomed...

Thanks!

MustangVixenGT

Nailed any curbs really hard lately?

dlazrael

nope, never curbed her since ive had her

Cruzinaround

Possibly a wheel bearing. Get it on a jack stand. Hug the wheel and try to wiggle it up and down vertically to see if there is any play.

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dlazrael

After some more research and another day having to drive to work, i've decided to go ahead and get a wheel hub assy and new brakes... I wanted to upgrade the brakes anyhow, so might as well use this as an excuse. For now I went with AM's powerstop kit, sometime late next year I plan on going with a brembo 6 piston, just don't have $2k lying around for brakes.... Hopefully (finally) next check I'll be able to get the bloody parts for my whipple and get that put in too!

Cruzinaround

So you're thinking it was a bearing?

dlazrael

Yea, the noise has gotten progessively worse, and its not the typical "humming" that people talk about, its a rotational noise that is affected by speed, and in both turns and straight lines... I did isolate it to the left front, but plan on doing both wheel bearings just in case.. I liken it to the horrible roads on the capital beltway here in DC/MD

dlazrael

So the bearing had a sticky grating feel to it, but when cracked open didnt seem to have anything going on that was noticable. However the LR Brake was metal to metal on the inside, which explains the groaning sound... sortof (sounded like it was LF not LR). Once I go back outside after lunch and finish the right side ill take it out and see if the sounds are gone!


PS WHOEVER DESIGNED THE REAR PISTON SYSTEM NEEDS TO BE SHOT! THE TOOL KEPT SLIPPING OUT AND TOOK ALMOST 2 HRS TO COLLAPSE!

TheDivaDanielle

just sounded like me that the pads were worn out.

dlazrael

the grinding (pads) was rear, but there was a noticeable rotational metal rattling sound on front left only, it's wierd..

on a different note, i cant get the damned rear caliper to collapse any further and its not collapsed enough to install the new brakes, so IDK WTF to do