Identify this nut ? (1 Viewer)

[Shyrock]

I found this in the crease of the seat in 2018 4Runner yesterday.
It's not a nut I have removed.
Had an alignment done a couple of weeks ago. Would this have been removed for anything associated with that?
Or maybe just fell out of the mechanic's pocket?

 

[r2m]

That's the only nut used to hold your entire car together!!!

 

[gnob]

Loose nut behind the wheel?

 

[r2m]

Seriously, here are some thoughts about it:

• It looks to be a pretty heavy duty nut, which suggests that whatever it's retaining, may be either important, heavy, subject to vibration or all three.
• Take a quick look under your seats, and then crawl under your dash and see if you can jiggle anything around while looking for any threads without nut.
• Being on the seat, do you leave your sunroof open and could it have just dropped in? I know thinks sometimes can get kicked up on the road pretty high and hard. It wouldn't be that much of a reach to think that was kick out from the road and dropped in.
• Are there any scuffs on it like it's been lying in the road or in a repair shop?

Just some thoughts. In the end, it really could be just something from the tech's pocket.

 

[re_guderian]

Looks like a strut mount nut.

 

[r2m]

Looks like a strut mount nut.

That would make sense if it's from an alignment shop.

 

[lehiguy]

I'll second the upper strut mount. Without question, that's what it is.