If your tire pressures are okay and the vehicle is obviously pulling in one direction when you briefly let go of the steering wheel, [also if there is any indication of uneven wear on the tread of the front tires] check the wheel alignment. A good wheel alignment service center will identify and deal with any issues with pneumatic suspension.
If you have any kind of damage to your wheel rim, replace the rim. The vibration from a damaged rim will cause undo stress on bearings, etc. Look around for good used rims if a new one is too expensive for you.
Also, the '05 Uplander sway bar links on the front end are prone to premature failure. It is not an expensive item to fix. I had both replaced on my '05 within 3 years, 60,000kms. I had a rattle underneath my vehicle each time that the links failed.
Consider replacing the links with a good after market product rather than the so called GM certified parts. In fact, where possible and practical, use good quality after market products rather than GM parts, as the after market product are often more superior in performance and quality.