It's road noise caused by deep tread depth. This is more common with off road type tires with agrressive tread design.
Check tires -I did check the tires, cleaned off the drum brakes, checked the shocks, everything is in order but the noise continues to get louder-
You would have to do time travel back about 45 years to find any Grasshopper tires today.
If the noise is similar to that of loud tires it more than likely that the wheel bearing hub or hubs. Sometimes if the noise goes away entering/exiting on a ramp it will definitely be the fore mention.
The humming noise is dependant on the road surface/ tire tread and tire wear. If the tires are scalloped or feathered they will hum. Vibration may be a problem in your suspension or the balancing of one or more of your tires. You can run your hand over the tread (front to back and back to front) if it is wavy or the tread feels jagged/ sharper in 1 direction, you need suspension work and/or an alignment.
move back tires to front and front tires to back
Engine Horn Muffler Stereo Brakes Tires
Depends on the kind of grinding. The brakes may have been messed with, so you'll getting a constant grinding noise. If the noise is audible when you first turn the vehicle on and it not in motion, then you have other problems. If you only hear it while the vehicle is in motion, then you should take it back to the shop where you got your tires replaced.
It could be the rear differential--there was a recall on this back in 2005--hope this helps
Depends of what kind of "Noise" you're hearing. Maybe try jacking your van up and shaking your tires back and forth to see if your ball joints, or any connecting rods are loose.
There are a couple of reasons why a 2001 Audi would make humming noises from the back while it is being driven. The first thing to check is the tires. If the tires are fine, check the wheel bearings.
Could be that your rear struts are bad and are allowing the car to squat enough when weight is added for the tires to rub the body or frame
Tractors have small tires on the front to make it easier to steer the tractor. Large tires are harder to steer. The large tires in the back allow the tractor to have more power as it plows.