Help ID Mystery Nut/End Plug That Fell Out Of Front Of Motor

[Archaeor]

I pulled off my front bumper to install new factory brush guard and tow hooks with appropriate brackets. When I went to test install (shoved in the new bumper/guard/brackets) to see if was a good fit, this thing fell out.  I'm pretty sure it was a part that the PO let fall into all the rubber mats, or front skid plate etc. underneath the front of the truck and never retrieved, but I would still like to know what it is.  5/16 or 16mm.

 

Thanks,

 

Rick

 

[fiatslug87]

Is it the bung for the transmission cooler lines in the radiator?

[Archaeor]

That's what it looks like to me, but I'm manual tranny.  Although, radiators can be universal (manual/auto) so maybe you're right!  I'll look underneath my radiator tomorrow and see if it's the same as any "bungs" there.  I'm sure it's just a "lost part", but nice to know which one... :) 

[Strokermjcomanche]

Power steering fitting for the return hose ?

[fiatslug87]

Are you installing the brush guard you got from Craig's list? Post some pictures.

[DirtyComanche]

Pretty certain that will be the plug for the trans cooler part of the rad, as 'almost' all rads come with the trans cooler in them and just have them plugged if you aren't using it. It's inverted flare, not much else uses inverted flare (nothing I can think of on an XJ/MJ, except brakes, which that is not).

[Archaeor]

It came out of the lower driver's side back of radiator.  Got it back in!

 

Thanks,

 

Rick

[DirtyComanche]

Yeah, that's the built in trans cooler. :thumbsup: