An UPPER?!?!?! Got pics? Recommend starting a thread about that, since it's a rare failure and I'm wondering if corrosion was involved to weaken it. Sometimes the first failure like this indicates a trend we'll be seeing many more of in the future.
I think corrosion played a part since there is some rust on there, but it is surface more than anything. Solid metal underneath and nothing crusty at the break. When I replaced my rear axle with the 8.6" last year I made sure to use the best 4 arms that had the least amount of rust. Most that any of the 4 have is surface rust.
It wasn't that way before Friday afternoon. When I hit the hole and it broke I was accelerating onto the interstate, and it about threw me into the semi next to me. Driving straight it feels about normal (aside from my front end being out of alignment now) but accelerate more than moderately and the axle twists around making it push in directions other than just straight ahead. Not fun. I'm hoping that the only damage is this trailing arm and needing realigned, and not something bent up front also.
They shipped it same day, $50 shipped to my door. Used, so it didn't have to be reprogrammed. It was a pain in the to pull my old one out, I almost had to take apart my entire dash but I was able to wiggle the original one out around the wires since it wasn't secured to the vehicle.
Just tell them you don't want one off of a 2002 (since those apparently go bad faster?) Mine came from an 03. Tell them the full name as it didn't come up under TCCM in their system.