sounds like your Power Steering pump is going out, I just replaced mine, cost was $500, unless you do it yourself then it's like $200.
could be your wheel bearings
change your wheel bearing!!
you might want to check your left side wheel bearings
posibly needs a new axle cv is bad
If its making a horrible grinding noise, it could be the bearing!
when turning or when ridin?
Bad wheel bearings usually cause a grinding noise, and are known to only cause it when turning.
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.
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.
Might be worn drive shafts or loose wheel nut
water/friction
I fixed my own problem. The left wheel bearing was bad it cost right at 200.00 dollars doing it myself.