Since 2016, my 2001 V70 xc has been emitting a knock when I reverse, often quite loud. About a full second after accelerating into reverse.

A transmission shop (2 fellows looking/listening to reverses) diagnosed multiple engine mounts. I replaced the lower one, which was sheared in half! But no change to knock.

Later, 2 different shops diagnosed the sleeve in the angle gear, i.e., worn teeth. But I am not convinced.

1. Could worn teeth impair reverse gear alone?

2. The angle gear is located beneath the driver, but the knock sounds like it’s coming from the rear axle.

Opinions?

 

dunno about gears making knock sounds. I'd look at a) motor mounts b) transmission & differential mounts c) exhaust system hangers