I'm getting a single "thump" that can be felt through the steering wheel and the brake pedal during hard braking.

To me it seems like a bad radius rod bushing but I just put new ones in. Beck/Arnley brand rubber bushings (not poly). Just checked them and they are torqued down nice and tight.

I don't get the sound/feel under any other conditions (bouncing the suspension, rough roads, acceleration, light braking).

I tried checking the ball joints for play but I can't feel any movement in the tire with the control arm jacked up. Both ball joints have been replaced.

Any other suggestions are appreciated!

93 Accord EX 5-speed.

 

It's possible the lower control arm bushings are worn and the through bolts are banging against the arm. Radius rod bushings are built to last. It's not likely you will ever need to replace those again. The only thing that goes wrong with those is they need to be greased to prevent squeaky noises.

You will need to get down there and look at what's going on.

 

With the help of a nearby shop I finally found the noise. The upper control arm pivot bolts were loose.

When I bought the UCAs, I assumed these bolts were tight since the whole thing comes as an assembly. A bad assumption, it turns out. These need to be torqued down tight when there's weight on the wheels, so I suppose that's why they come loose.