I've got an 86.5 Nissan Truck 4x2 thats making a very annoying popping
sound from the front left suspension.  It happens when:

- switching directions (forward to reverse and vice versa) when using
the brakes (more so with the wheels turned)
- releasing the brakes after coming to a stop (and then accelerating)
- easing up on the brakes after braking hard
- taking sharp turns in a parking lot

The front end also feels a little "loose" when driving over speed
bumps or entering driveways at an angle.  I've noticed a little play
in the wheels when grabbing the top of the tire and I push/pull on it,
but I'm told that its within spec.  I don't seem to get an axial play
though.

I've had the upper control arm bushing replace, the tension rod
bushings replaced, and also new shocks.

Anyone got any ideas what could be causing this?  I torqued all the
front suspension to spec about a year ago.  Could loose wheel bearings
or ball joints cause this?  I don't seem to get any other kind of noise.

Thanks,
Dave