Hi all, hate that my first post here is a cry for help, but the community here seems a lot more savvy than the Reddit folks I’ve been attacking this with.
1999 4Runner Limited 2WD ~120,000 single owner til I purchased it in January. It’s been nothing short of a dream and love how easy it is to work on (For the most part)

my issue now is thus centralized metallic rattling that centers around the shifter to the passenger footwell side. 9 times out of 10 I can do my 10 mile commute round trip without triggering it, but if I stop really hard or hit a substantial speed bump/pothole, than the rattle begins. It’s amplitude seems to match the RPM of the driveshaft, and it’ll increase or decrease with the vehicles speed. It’ll will eventually stop with a climactic clank and then will be silent til jostled again.

I’ve bounced from checking every heat shield underneath and couldn’t find anything near the spot I hear it at that was loose.

Today I re-attacked the issue and removed the cat/front half of the exhaust attached at the manifold. My hunch was that there was a baffle loose in the cat but I took it off and shook it and nothing was loose….

my relatively amateur eye couldn’t find anything visually wrong with the driveline either….

attached are the link to the video of my noise, photo of the inside of the cat, and my current troubleshooting setup.



All advice welcomed!

 

Flywheel coming apart? A piece of gravel stuck between rotor & dust shield? Something broken or unhooked in one of the drum brakes?


Andreas

 

That's not a rattle, that's grating/grinding. Something metal is spinning against something else metal. Not rattling. At least to my ear. Whether it's internal to a transmission/gear box or external is the next question...so in that sense you're doing the right thing by checking for loose stuff. So Andreas is on the right track with something getting caught on something that's spinning.

But I'd focus on something contacting the driveshaft. Could be brake/wheel-related, since noises can telegraph, but it sure sounds like it's coming from very near the tranny/t-case.

 

Thanks folks, going underneath now: Going to check for any unwanted contact with the driveline, and the rotor + covers.

From sifting YouTube for various ticks and noises, found a torque converter tinging that sounds just like mine (Probably going to be beyond my purview as I’ve got hand tools and some car ramps as far as accoutrements go)

Going to try to find some write-ups from flywheel replacement and t-converter work. Just to gain an understanding.

 

I haven't tried on my 4Runners, but I think that one can insert an endoscope through an access in the bell housing to see if any flywheel cracks are present.
someone correct me if I'm wrong.



Andreas

 

One thing I realized to keep in mind is that since the problem is intermittent, there may not be anything visually obvious. If it scrapes and clangs then goes away, you may not see anything contacting the driveshaft or whatever it ends up being. Your description sounds a lot like a rock getting stuck in wheel/brakes, then coming out, but it wouldn't make sense to keep happening regularly, I don't think.

 

Couldn’t find any points of contact underneath it and put the cat back on because it clearly didn’t have any loose internals… Not sure what else I can do from home so it might be time to send her in to a shop that can peel it open to look at the torque converter.

 

How about setting the rear axle on a set of stands, blocking the front wheels, and then slowly getting it up to speed in "D"?


Andreas

 

I had a nearly identical sound on my Tacoma. Turned out to be one of the straps for the gas tank broke and would rest on the driveshaft making noise as it spun along.

 

Hey Y'all,
I have a '93 4runner 2wd that is making the same sound, particularly after going over a speed bump or train tracks. It comes and goes, so i have not been able to pin point it. Did anyone figure out if it was the torque converter and/or the catalytic converter? I appreciate the help.

 

Sorry for not completing the circle here gents!
I left on a 2 week work trip, the wife couldn’t take it anymore and took it in… Turns out *Drum roll*

it was a loose metal seal on the steering column that had sheared off at some point between now and -99. $60 for them to peel it open and take it off.

it was super benign and I was infinitely surprised at how little of an issue it was

 

I like this but have trouble believing it, which metal shield for the column.

 

I definitely would not have thought about looking there, I'll get under the car today. I appreciate the help.