Handling on a worn out rear beam?

[powerandtorque]

How would I go about finding out about a stub axle?

Generally speaking, you normally end up bending stub axles by sliding sideways into curbs and the like.

It's hard to accurately check them on the car if they're only slightly bent, but usually the give away is that a bent stub axle will normally end up giving positive camber (sometimes with some "interesting" toe angles) whereas a dead trailing arm shaft and bearings gives excessive negative camber.

A bent stub axle will also leave the brake disk running out of true with the caliper and brake pads, so you'll sometimes get brake binding or odd brake pad wear too.