can any body help?? i drive to the store,on level ground and put in park and shut the engine off. come back out and start the engine and a loud noise in the tranmisson, kinded like when you put it in park the trans locks and wont roll, it fell like when i shut the truck down it get sometime stuck in the middle and it go bang,hope that make since.should i take it in to the stillership or could i fix it,all fluids are full,i dont know what to do,thanks for any help.