posibly needs a new axle cv is bad
not sure sound like it comes from front suspension
you might want to check your left side wheel bearings
when turning or when ridin?
Are you sure the noise isn't in the front. Sounds like a right front wheel bearing,which is a common problem on these vans.
Front drive axle joints bad
tie rod
If the noise is a clicking sound, chances are the CV shaft (or axle shaft) is bad. It supplies power from the trans axle to the wheel.
The front wheel bearing is bad. The sound will be more pronounced when turning one way but not the other. The bad bearing is on the side of the car opposite the turning since more weight is on that side of the car when turning.
that is either your front right wheel bearing or your coil spring is turning need new suspension..$$$$
Wheel bearings or u joints
A Geo Metro is a front wheel drive vehicle. When a squealing noise occurs when the wheel is turning, it can be an indication of damage to the CV joints.
water/friction