messing with my 2006 LT trailer hitch which is rust welded together, I got a LOT of rusted chunks of metal fall out from what looks like inside the bumper. I suspect it is the crash bar across the back (??) and inside the bumper. Am I best to just leave it alone or what? I suspect the trailer hitch may be holding things together. I am not able to take a look under there due to medical reasons. open to guesses and suggestions...

 

The rear bumper reinforcement bar does tent to get rusty after a decade . The trailer hitch bolts to the frame rails back there . It’s fine
I believe that bumper bar is now obsolete, from GM

 

Of course it is... is there a replacement or do I need to start checking junk yards? or find a sturdy tree and start carving..

If I had a pattern, I could weld one together...

 

Road salt has a direct path from under the back tire to the inside crash bar/steel bumper... don't ask how I know.

 

I wonder if living in Ohio has anything to do with it.

 

Well I don't know much about Ohio, but here in Minnesota, we have plenty of salted slush filled months and we call it the Minnesota weight reduction plan. Makes your car much lighter and get better miles per gallon.. (Ha Ha) I know because I also drive Land Rovers, and most vehicles that are at least 10+ years old. add that to not having a garage, or even a driveway and well, you get the idea. I just like older vehicles...

GMpartsdirect does list the part and a price, so I assume it isn't discontinued..

https://www.gmpartsdirect.com/oem-pa...t-bar-25931602

 

If you open that link and scroll down, it is listed as a special order part, they just haven’t listed it as obsolete

 

I see.. Thank you

 

Ask around your local body shops for after market body parts suppliers.

 

i got this problem
my amplifier bumper rotted too, just crumbles in my hands
the reason for such rapid decay is that road dirt is driven into the open cavity of the bumper by air turbulence when driving (design flaw)

What I've done:
firstly, I combed through the junkyards and found the bumper reinforcement, almost untouched by rust;
secondly, I removed the incipient reddish foci to the bare metal, then took a "primer-enamel on rust" and painted over the entire part inside and out with a brush in several layers so that the thickness of the paint layer was significant;
thirdly, I bought the so-called Movil (something like a resin specifically for corrosion protection of a car body) and generously missed the bumper reinforcement from the inside;
then I think that I will fill the inside of the bumper amplifier with construction foam so that water does not have a chance to penetrate into the bumper at all ... But I have not yet decided whether it is worth doing. So far, no one has confirmed to me the wisdom of such a step.