really hard to explain, but all of a sudden there is something really wrong with me truck. Went hunting yesterday and got into a little bit of mud so I locked in my 4 wheel drive (dont know if this has anything to do with it). anyways today take the truck out and when I hit the brakes I hear one quick thumping sound underneath, almost like a switch turning on and off but really loud. when I go to brake it seems like the brakes are almost starting to grind then I quick stop. when I take off its almost a jump start to get going. Just driving around I can hear something that sounds really loose under the front end, but when i stop and climb underneath I find nothing. Tried to keep going in and out of 4 wheel drive and various other acts. Sounds weird but the truck does everything perfect when I go backwards. This is a 2004 screw by the way. Anybody have any suggestions? thanks for any suggestions up front

 

Pull the tires off a inspect the brakes.

 

thanks turkey hunter. took off the passenger wheel to inspect brakes. dont know how it happened but the lower bolt that actually holds everything on to the frame was gone. I am thinking this was the problem. guess it could have been pretty dangerous down the road.. thanks

 

i had the exact same sound and it was the brakes in my saab 9-3 convertible... although i wasn't mudding in a convertible .