I have a 940 and just replaced the pipe that goes over the rearaxle. I have tightened the clamp only moderately tight and for now there is a bit of exhaust leaking out. I don't want to go super tight until I replace the muffler too. My clamp is one I bought at Advanced Auto. Looking at it, I am wondering how it can possibly provide equal pressure as a clamp around the entire circumference of the pipes. It would seem that the pressure would not be evenly applied. Which leads to my question. Is the purpose of the clamp to deform the outermost pipe permanently in order to form a seal by mashing the metal from the outermost pipe into the metal of the innermost? Or should there be a seal that forms even without the clamp because the innermost outside diameter matches the outermost pipe's inside diameter? Also, is there a 'best' type of clamp to use instead of the cheapo one I have. One other question: what do most people use to cut off the old rusty clamps? I've given up on trying to unbolt old clamps. Thanks.