1990 Miata - guess the clunk

First, I successfully swapped on a new top on the Miata today. Literally every single muscle hurts. Especially fingers and forearms (wait, what?). Anyway, it looks great for now. Very tight, I hope it relaxes a bit in the sun over the next few days. I had to adjust the latches all the way loose to get it to close, and it's still difficult.

Next, the real point of this thread, guess the clunk.

Rear driver side. If I bounce the car in my driveway, I hear the clunk. If I drive between 55-75 mph, it rattles. I'm pretty sure it's the same root cause. If I shake the crap out of the exhaust, I get no interference, so I'm pretty sure it's not that.

I just swapped in a used strut, so I am reasonably sure the strut top mount and bottom bolt are not the issue.

Go!

Could it be the upper mount is not tight enough to the shock? Not the upper mount to the body. On my 96 I didn't get the spring compressed enough before I put the mount and nut on. So I got a clunk / rattle

In reply to rustybugkiller:

Possible. I forgot to mention I had the same clunk before and after the rear strut swap, so it's possible, but unlikely with two different struts, right?

Check under the carpet and see if the hardware holding the jack is tight...

Congrats on getting the top done! I dread the day that I finally get around to doing that....

Does the parking brake being engaged or not change the clunk? Could it be the dust shield?

cmcgregor wrote: Congrats on getting the top done! I dread the day that I finally get around to doing that.... Does the parking brake being engaged or not change the clunk? Could it be the dust shield?

Don't dread it. I've done it 3 times, it's really not bad. Just do it on a hot summer day so things stretch.

In reply to Rodan:

Jack is tight. I wish that were the answer. too bad.

In reply to cmcgregor:

I'll check with parking brake on and off. Good call.

the top isn't bad, but leave a whole day to do it the first time. I really struggled getting the bolts that hold the back of the top and rain rail on, since the material is tight it wants to prevent you from getting the nuts started unless you push HARD.

I'd say do it on a hot day, but holy cow was it hot INSIDE as I was trying to get said nuts started. and it was about 70 here yesterday.

oh, and if you are "speedy-riviting" a new rain rail onto the new top, make sure to use a metal dolly behind the rivets. I started with a piece of hardwood, thinking it would be fine, and then I wasted about 4 rivets. Had to go to the store (try Jo-Ann Fabrics, not Home Depot) to get more.

The instructions that came with the top were great too.

In reply to Robbie:

Swaybar end link, or broken swaybar bracket?

Pete Gossett wrote: In reply to Robbie: Swaybar end link, or broken swaybar bracket?

That was my next guess

cmcgregor wrote:

Pete Gossett wrote: In reply to Robbie: Swaybar end link, or broken swaybar bracket?

That was my next guess

Or even loose way bar link bolts. When they loosen up, they make a helluva racket.

If you can make it clunk by bouncing it, enlist a helper. You'll be able to find it.

Did it clunk before you did the strut swap? If so, that's not it. If not, most likely the opposite.

Bowling ball loose in the trunk?

Did you ever figure out the clunk?

cmcgregor wrote: Did you ever figure out the clunk?

Not yet. I've been sidetracked by house issues for a bit, just haven't gotten to it.

It's a very weird noise though. Sounds like a weed wacker hitting a loose piece of metal siding. EDIT: not when I bounce the car in the driveway, but rather when I am going between about 55 and 75.

Very curious. I know you said you aren't getting any PPF/exhaust contact, but could it be hitting the diff?

There are a lot of potential causes (and solutions) for the 55-75 Miata shake - which you may have a minor case of, but you can usually feel that in the steering wheel as well, and as far as I can remember that's not the case here.

Robbie wrote: Sounds like a weed wacker hitting a loose piece of metal siding.

This screams heat shield.

Or maybe that gas filler tube shield thingy that you removed for shock access in the trunk?

Robbie wrote: I'd say do it on a hot day, but holy cow was it hot INSIDE as I was trying to get said nuts started. and it was about 70 here yesterday.

The best thing I've found is to do all of the work in the garage, then roll it outside for an hour before you try to close it all up.

A group of us at work are trying to plan a top-day.. We've got 3 or 4 that need done.