we were driving home this evening after a day at the range, which involved driving about 2 miles on a gravel road and a mile on a bumpy dirt road

on our hour drive home, we noticed a "vibrating rattle underneath the floorboard which sounded like metal vibrating against metal" (my wife's description), which we initially noticed while exiting the interstate and slowing to a stop about fifteen miles from home, and then it got progressively more noticeable on bumps such as crossing over railroad tracks or other pavement imperfections

we both thought the skid plates might have come loose (particularly because just last night I had actually realized that I don't even have all the skid plate bolts installed - apparently based on THIS THREAD, now I know that I am missing the two bolts holding the back of the rear plate), so the first thing we checked once we pulled into the garage was the skid plates, but they seem to still be solidly attached to the 4Runner...

I realize this is a very generic description, but can anybody give me any ideas on what else I should inspect to diagnose this "vibrating metal-on-metal rattle" which we heard and felt underneath the floorboard?

thanks in advance!

You could remove the skids and see if your sound goes away.

I plan to get under there in the morning to remove the skids (have to change the oil anyway) and see whether I can determine anything... but I was hoping to get any tips on anything specific to look for while I was under there...?

I reckon it's one of the heat shields on one of your cats. I think they rust through the day after the truck rolls off the line... Lemme know what it turns out to be!

Check out the heat shields on the exhaust. I have the same noise and i have one bolt out of 4 holding one of the heat shields on. I just can't get it off so I've been spraying PB Blaster all over it

thanks, I'll check that out now as soon as I finish breakfast, but any chance somebody could post a photo just so I can ensure I'm looking for/at the correct part(s)?

the heat shields seem solid and do not rattle

I removed the rear skid plate and will drive to Ace hardware now to get the two rear bolts I was missing, so on the way to the store I will listen whether I still have the vibrating metal-on-metal rattle... but nothing else underneath the truck seems loose at this point...

Did you check the heat shields not only on the cats, but attached to the bottom on the body? Sorry I didn't manage to take a picture, I had planned to but got balls deep in my maintenance project right after breakfast and forgot all about ya.


-Tyler

thanks for the tip; I'll check those too...

Had the same problem. Took all bolts(badly rusted) off cat shield and replaced with stainless. Problem solved.

so something as simple as rusty bolts would cause all this clanking and clanging underneath?

how many bolts are we talking about...?

my truck developed a rattle underneath too. gotta chk out the bolt

The steering rack bushings were one of my rattles. I think it was the clunk when hitting the tar lines in pavement. I got those replaced and now it just transmits a different vibration that it didn't before.

I had two front end rattles when I bought my 2002 T4R.
One was a loose skid plate bolt.

The other was this!
Anti sway bar bushing totally shot.
Good idea to check these out while you are under there.

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mine turned out to be the heat shield under the exhaust.......bolts were rusted, replaced them and my truck is rattle free now.....ut was a quick n easy fix...just go under the car..u will see the loose heat shield