NB front end "clunk" - what to check?

So I've got an annoying clunk in the front end; seems to happen with forward/aft movement, but not consistently.

When it was consistent with steering movement, it did lead me to find my wheel bearing were bad, so I replaced those. But, again, now it's intermittent.

Then I tightened up the upper front control arms, figuring maybe I left them a little loose after getting rid of the satan(race)land coilovers.

I just put sways on it (in spite of FM's admonition to try the settings before moving to "full stiff" I set the rear bar that way - I likes my tail happy cars...), should be tight, but the front brackets were a funny shape - seem like they had some interference with the bolt heads - I'll check that again.

Miata.net searching seems like rack bushings or the control arm eccentrics, I'll try those next...

Anything else to check?

I had Moog end links on my NB. They came with grease fittings and those fittings would come in contact with the springs. I filled them with grease and then removed the fittings and plugged the holes.

Or... do you have something like this? Because they will never be quiet.

I don't have the nifty end links, just stockers, but man those sure look beefy.

I heard a bit of a knock while turning yesterday, but it still mostly occurs when moving fore/aft.

I'll have to just nut and bolt a few more things, see if it clears up.

Drives me bananas.

Checked the swaybar mounts for cracks? They can fail with aftermarket bars.

In reply to thatsnowinnebago:

I was going to say this too. Also, check to be sure the swaybar bushings aren't dry or binding.

EDIT: Oh, and turn on the Keith Tanner Miata "Bat signal", so he knows a Miata owner is in danger.

thatsnowinnebego - I just put the FM sways on, so shouldn't be any thing with the mounts mounts due to that - except that the bar to frame "u" brackets are just wide enough at the bend that they seem to interfere at the bolt head - they certainly felt and looked like they were snug though.

kazoospec - the bushings shouldn't be dry - I liberally applied the grease that comes with them - no squeeking or anything. And, just installed, to further the "it shouldn't be dry just yet..." rationale.

All said and done though, I can't say I notice any clunking over bumps that might engage the sways (i.e. diagonal to the direction of travel) - just occasionally with initial start of forward movement, or backing up a little.

And I think GRM needs to insert some sw code in the board here that automatically notifies Keith with a link to the post whenever the words "MX5 Signal" are typed... (Should that be a new thread? What are the words for the "bat signal" to Keith?)

I want a bat signal!

Easy way to check to see if it's the sways - disconnect the end links. Sway bar end links tend to make more of a rattle, similar to a loose upper shock bolt.

Sounds like it could be brake pads moving in the calipers if it's related to the start of wheel movement. There are springs and clips intended to minimize this. Or a caliper that's not firmly bolted in. But I'd start with the pads.

Ball joints tend to make deep clunking noises on cornering, as that's the greatest load they usually see.

Kinda off the wall but what about your PPF bolts? Are they all tight?

thatsnowinnebago wrote: Kinda off the wall but what about your PPF bolts? Are they all tight?

PPF bolts? 'Splain, Lucy.

The brake pad thing is interesting... just new clips to hold the pads in, in that case?

Power Plant Frame. It's the big girder that connects the trans to the diff. They're locked into place with some sleeves, so that's unlikely. But if you're under the car, easy to check.

I'd certainly check that all the clips are there. They're easy to lose on a brake change.

So, crazy day, and the boy and I are looking to autocross tomorrow; I wanted to take the Miata but the clunk bothered me.

So I jack up the car, and check my lower control arm bolts/eccentrics. Passenger side is tight, but drivers side, front eccentric I can turn with the torque wrench. It's loose alright, and may well be the sound I've been hearing.

However, I didn't expect wholesale movement of the bolt, so as I gave the wrench a good tug, I just twisted the car out of alignment.

Won't be taking the Miata to the autocross...

Crank that E36 M3 all the way negative camber and run it. Done

In reply to OldGray320i:

I had that happen with one of the rear eccentrics on my old track car. The whole lower control arm was moving from one end of the adjustable range to the other in the Esses at Lime Rock with a big clunk.

I've been told that the torque spec on Miata alignment bolts is "the biggest guy in the shop on the end of the longest breaker bar". That's also why I always clean the eccentrics before going in for an alignment and then make reference marks on them before leaving the shop. It makes it easy to fix the alignment at the track if something loosens up.

I just bought a full set of the camber eccentric bolts because I read that they are a semi consumable item.