alright i have a 1997 ford f150 4x4 4.6v8....and it seems that everytime im at a stop light or stop sign and i start to accerlate there is a clunk that happens right away and then goes away...any ideas what that is?

 

My first guess would be U-joint.

 

thats what i thought but i replaced that so its brand new and its still doing it

 

I also have 1997 4x4 4.6 which does the same thing. It is not just confined to 1997 model year as later models can also have the problem. Some of these trucks have a condition that entails a sticking of the trans/driveshaft spline when the truck moves forward from a stop. When the driveshaft moves rearward from acceleration the spline momentarily sticks and it makes a clunk noise. There is a TSB that explains a temporary fix. Basicly you have too drop the driveshaft and clean the female (transmission end) of the shaft with degreaser. Then apply Teflon grease inside the spline end that you just cleaned and reinstall the driveshaft. I have performed this "fix" several times since I've owned my truck. It comes back after a while and if it continues to bother you than you perform the grease job again....there is no durability or damage done to the truck from the condition. At least none that I am aware of. Good luck.