I own a 2007 Uplander and for sone time I have been hearing a rather loud knocking/clunking sound from underneath. I originally thought it may be shocks and struts but they seem to be fine. The noise itself seems to be originating from right under or behind the two front seats or closer to the rear. Any one have any ideas what is causing this noise...thank you in advance for any responses

 

I would check the trailing arm bushings

 

Front sway bar links are my first guess.

 

I have 2008 Uplander it has a knock in the front right I can't find I replace the strut and a CV axle
it doesn't do it hitting a bump but it does it turning accelerating decelerating and braking. I took a big pry bar check the ball joint the control arm bushings and the sway bar bushings try to get something to move and make the noise. This is getting to be a hard one

 

I have 2008 Uplander it has a knock in the front right I can't find I replace the strut and a CV axle
it doesn't do it hitting a bump but it does it turning accelerating decelerating and braking. I took a big pry bar check the ball joint the control arm bushings and the sway bar bushings try to get something to move and make the noise. This is getting to be a hard one

 

Thanks Gentleman...noise is cominh from the back end...I have already replaced sway bar links on the front end,this noise has nothng to do with front end all in the rear...I have replaced all suspension parts in the rear noise is still present and I have been told it could ve the rear trailing arm bushings. At this point all this vehicle needs to do for me is survive until march/april....van only has 212,000 km on it and it has the " WORST" vehicle I have ever owned...unfortunately I will never own another GM after this vehicle....but thank you to all that responded...

 

It might be from the parking brake cable equalizer knocking on the frame. I spent months and days and finally find it out, because when you park your car and apply parking brake, the cable is tightened, and the equalizer is lift up. When the car is running, the brake cable is released and the equalizer left hanging there, and may knock on the frame.

See if that's your case. If yes, you can use an insulator. (called: insulator, brake rod)