[jaydow11]

Originally Posted by Draco-REX

Ding! Give the man a cigar!

Most cars have one piston for the brakes. In order to apply even force to both sides of the disc, the caliper slides on pins so that it can grip both sides. Our calipers have pistons on both sides of the disc. Because of this, the calipers are fixed and there is no active force keeping the pads against the rotor face. When you change direction, the pads can shift in the caliper. This makes a clunking sound as they settle into the new position for the current wheel rotation. The clunking shouldn't happen again if you touch the brakes again after continuing in the same direction; only after *changing* direction.

There should be threads on "Brake Clunk" and you can also look into "Pad Knockback"

The only other clunk source that occurs only when changing direction is loose axle nuts. But I'd bet on brake clunk first.

Interesting! Is there a reason why this would "all of a sudden" start to happen? I haven't changed anything to do with the breaks/pads. Does this happen as the breaks wear down?

Thanks,

jay

[Draco-REX]

Originally Posted by jaydow11

Interesting! Is there a reason why this would "all of a sudden" start to happen? I haven't changed anything to do with the breaks/pads. Does this happen as the breaks wear down?

Thanks,

jay

Well, slimmer pads will allow more knockback. Also, sometimes things like this are always present, but it's not until you start paying attention to it do you notice it. The brake clunk doesn't happen to everyone either. Some say they never had it with the stock pads, but got it with replacement pads. Some say it was the opposite with the OEMs being quiet. My OEM pads clunk, but it's just the nature of performance brakes.

[jaydow11]

Originally Posted by Draco-REX

Well, slimmer pads will allow more knockback. Also, sometimes things like this are always present, but it's not until you start paying attention to it do you notice it. The brake clunk doesn't happen to everyone either. Some say they never had it with the stock pads, but got it with replacement pads. Some say it was the opposite with the OEMs being quiet. My OEM pads clunk, but it's just the nature of performance brakes.

Thanks for the info! However, after thinking about it... I really don't think my clunk is related to the breaks. I feel it in the middle of the car.

The best way I can discribe the clunk/tap is a bolt that is being pulled though part of the frame by the force of the car moving and slipping by one thread.

So you are pulling and or pushing a bolt though a hole it's catching one thread and clunking/taping each time.

I'm not sure if that makes sense or not??

Anyways, I have an appointment at the dealership on Friday for them to try and solve it... However, I would rather try and find the problem myself so I don't have to pay them $100/hour for their time


Like i said before, they think the problem is coming from the top of the spring hitting part of the tophat/housing because it looks like the rubber padding has shifted from it's proper place...

Again, it I can't see it being that based on the type of sound it makes and when it makes it.

If it really was the top of the spring, it should be making a sound every time the spring moves, but it doesn't...

I'm almost going back to the possiblity of it being the swaybar brackets. I drilled out all 4 of them and replaced them with brand new bolts and nuts.

However, I'm wondering since the new bottom bolts aren't actually fixed to the frame like they usually are, there may be some play in there that is allowing movement (even though they are on there really, really, tight)

I'm just trying to figure out what forces are in play when stopping or accelerating that would cause this clunk.

Because If I'm just driving down the road, even a really rough one, I don't hear it at all... Even if I'm really aggressive on the wheel going from side to side... no sound!

It's only when I'm in the process of stopping or accelerating.....

[gradualepiphany]

Yeah, which is why I suspected the brake pads - it REALLY sounds like that's what it is to me - it only seems to happen to you at times when the pads would be shifting foward or back. The sound / feel does seem to come from deeper in the car than you'd think, but that's because it's probably coming from more than one wheel at a time and the shock is being transmitted to your butt via suspension mounting points further towards the center of the car than your brakes are. My 1st set of stock pads knocked and squealed like mad - both of which mostly stopped after slathering them in disc brake quiet / brake lube. My 2nd set of pads aren't squealing so I haven't put anything on them (I was out of brake lube when I stuck em in), but they are knocking rather loudly. It isnt just a thud, it's kind of a scraping thud like a metal on metal tap combined with a tiny sharp fingernails-on-chalkboard squeak. It might sound different on other cars though.

[niemkij]

I can list a few other possibilities, but they are a long shot compared with what others have pointed out allready:
Loose trailing link bolts
Rear diff brackets loose
Rear diff broken or low on fluid?
Lateral links loose, possibly the rear toe adjustment bolt?

good luck!

[jaydow11]

Thanks guys! Last night I was lying in bed thinking about this and I'm going to start by taking the front swaybar off the car. I always am thinking "tighten" when I hear a clunk but in this case, I really need to know for sure that it's not the swaybar...

Not sure why I didn't think of taking it off sooner to make 100% sure it's not anything to do with that??

So if I take the swaybar right off the car, and the clunk is still there, then I'll be one step (out of 100) closer!

Again, if I haven't found the problem before Friday, it's going to the dealer for them to figure it out...

[2blue4usti]

15 pages of reading starting here> Excessive front endlink noise

Only if the clunk is resolved with the aftermarket bar off.

Note:
My clunk is and has been cured as the result of items listed in the above thread.
Blubyu

[jaydow11]

Originally Posted by 2blue4usti

15 pages of reading starting here> Excessive front endlink noise

Only if the clunk is resolved with the aftermarket bar off.

Note:
My clunk is and has been cured as the result of items listed in the above thread.
Blubyu

Yup! I have read through that thread when I first did my sways last year...

And I did find the clunk... and it is in the front sways somewhere as I took it right off the car and drove it around the block... sweet silence!

SO now I just have to figure out if it's coming from the brackets (which I think it is) or the endlinks...

Anyways the battle continues....

Cheers,

Jay

[2blue4usti]

Jay,

had a lot of experience on this one. Have not seen clunk from the brackets. Have seen and fixed several clunks from the endlinks. I think you said your using the stock endlinks, right? Gotta get aftermarket endlinks, especially if those have seen salt(Canada).
Kartboy, Kartboy, Kartboy with the spacers if this a 27-29mm bar. IMHO of course.