My wagon with 194k miles often makes a single loud bang/pop/whack noise when I start off in either drive or reverse-sounds like someone hitting the axle or trailing arm with a hammer. A really good Volvo shop has been working on it and so far they're stumped.

The noise definitely comes from the right rear hub. The shop owner rode in the right rear seat with the door open while I ran the car back and forth on smooth pavement. Then he walked next to it while I did the same thing. And he agrees with the source and the description. I get the noise when starting off going straight or turning left--never when turning right. Sometimes the rear end of the car actually moves or jerks just a bit at the moment I hear the noise.

Here's what the shop has checked: The handbrake shoes are not grabbing. The RR wheel bearing is ok. They swapped out the half-axle and the sound is just the same. The splines on the original half-axle look fine. They have checked the suspension bushings (torque rod bushings and axle end trailing arm bushing on the right side are relatively new)--everything is tight. They have checked the body-end mounts for the trailing and torque arms. None of the bushings is binding on its thru-bolt.

What's left to check?!

I sure would appreciate any help you can give.

Doug Harvey