Weird clunking...

[King_V]

All,

Ok, I can't figure this one out, though I can at least USUALLY reproduce it.

Sometimes when I come to an abrupt stop while moving fairly slowly, I'll hear a sort of "ka-chunk" or a clunk or something. Seems like it's coming from the front-driver's wheel or thereabouts.

Naturally, when I raise that wheel, or both front wheels, off the ground, no twisting, moving, or other manhandling of the wheel indicates anything's amiss.

I can basically get it to happen if I roll forward, giving it a little gas while on the driveway, then stop suddenly (no wheel lock). I hear a sort of clunking noise and it SEEMS as if the front driver's wheel twitches slightly.

If I then go backwards and brake suddenly, the noise is louder, and I see the twitch, but this doesn't happen 100% of the time.

ALMOST all of the time if I come to a stop, put it in reverse, then turn the wheel right, as to back into the driveway from the street, it'll do it.

Sometimes it coincides with stepping in the brake, sometimes it coincides with letting off the brake pedal. Sometimes it coincides with the actual change of direction (ie: forward to backward).

The noise seems to be getting a little worse - but otherwise the car doesn't seem to be adversely affected - it still tracks straight, etc.

It is, however, making me nervous. Any thoughts or suggestions?

Heck, even any known-and-trusted mechanics who're good with front-end stuff that are in my area that you'd recommend?

[gadget73]

if you've checked the wheel for play with the lower control arm supported on a jack, I'd suspect the rubber bushings in the caliper are shot, and you're hearing the caliper slopping back and forth a bit. I could give you a reccomendation for someone in PA if you're up for a drive to Scott.

[King_V]

Hrm, if I recall, Scott's a 2-1/2 to 3 hour drive from me! Otherwise he'd probably be the first person I'd see.

Ah, didn't try to check with the control-arm supported - basically had jackstands on the framerail behind the front wheels, and checked for play. There was none to be had - I could turn the wheels as if the steering wheel were being turned, but there was no slop, looseness, or anything that I could manage.

I'll check the bushings. If that's the case, I may replace the caliper itself, since I replaced the passenger side one less than a year ago.

[Bowman85merc]

Does it clunk when you go over a bump, or just when you suddenly jolt the brakes ???

If it doesn't clunk over bumps/potholes/etc., I would have to go with what Gadget said, the bushings are just getting old and worn out.

[gadget73]

If the suspension wasn't loaded, you won't find play in the ball joints. The springs put enough pressure on the arm that it tightens everything up. If you have a jack under the arm so its not on the bump stop, you'll find looseness if there is any there.

[Pirate]

Without looking at the car, I think you might have an upper control arm bushing on it's way out, if it isn't gone already.

[King_V]

It seems to happen, though less loudly, on occasion when I hit a bump, but that's very uncommon.

I'll try it with the jack under the control arm.

Did take a look at the caliper and didn't seem to see any issues with caliper slop trying to move things around by hand - but the caliper itself is noticeably tight (driver's wheel does not turn nearly as freely as passenger wheel), so it's gotta go anyway.

Naturally when I tried to examine it, once I got the wheel off and caliper unbolted, it started to rain....

[King_V]

Hrm, well, tried wiggling things about with the jack lifting the car via the lower-control-arm. I barely hit 140 lbs, so I can't exactly generate a whole lot of force on my own. My best efforts reveal no looseness or clunking.

However, I got to work on the brake caliper, which didn't go so well. See Fun with brakes!

[gadget73]

If its really loose, you'd know it. It doesn't require huge amounts of force to detect a really slopped out ball joint. I've seen some folks use a big pry bar or a piece of wood to pry against the tire to make more force, but usually if there is enough play to be concerned about, you can easily feel it just rocking the tire up and down by hand.

[King_V]

Hrm, well, no play . . and I was almost CONVINCED that the brakes were the issue what with the VERY strange wear pattern, physically damaged caliper, etc.

No luck, still clunking. Weird....

Note though that if I'm gentle on the car stopping, starting, backing up, moving forward, etc., it tends not to happen - the braking needs to be a little abrupt.

I've also tried to cut turns a little harder than usual to see if I could detect anything - nada. Just seems to happen either on braking or on initial acceleration after changing direction (forward to backward or vice versa) . . usually.

I *have* noticed now that the car seems to be pulling to the right a bit. I guess maybe whatever's happening affected my alignment, but the tight caliper compensated for it and made the car go straight.

[gadget73]

Did you check the brakes on the other side to make sure nothing is strange over there ?

[datto62073]

check teh brakes. i have heard brake clunk with very little movement of the cal. its weird when it happens.

[King_V]

Did you check the brakes on the other side to make sure nothing is strange over there ?

Will be doing that when the rain stops - changed the rotor and caliper on the other side a few months ago, though. But there doesn't appear to be any noise coming from that side... as best I can tell. Plus I have to put the new pads in on that side anyway (yeah, I changed them only on one side - was losing light fast when the hard line snapped originally!)

[King_V]

Ok, now this is getting weird.

Clunking's still there, and getting a little worse - BUT it doesn't happen if I do anything gently (braking, accelerating, reversing), I have to do it a little abruptly, AND I can't budge things to check.

Brought it to a mechanic. He's baffled as well. Says the front-left wheel is a little cockeyed, but nothing seems loose - BUT, my 6-month-old Sensatracs are leaking! (he already knew they were under warranty)

He also checked to make sure everything I did with the caliper, rotor, etc, was good and solid. Nothing wrong there, no looseness.

Curiouser and curiouser. He said he'll sneak in a little time tomorrow to take another look, but so far he's not only baffled, he can't consistently reproduce the problem!

Maddening! Well, maybe when I get the shocks redone under warranty, another set of eyes looking at the front end may help. I hope...

[Lincolnmania]

bring it up here......we will find it and fix it