Universal Joint, this bit that allows slight missalignment to be taken up without damage....
there are 2 at the fonrt and the most suseible one is the one at the fornt as it is right near teh down pipe and gets F hot, they come sealded lubed for life, but the heat baks then dry and they fook up, a good mod is to have a grease nipple fitted so that u can re grease it each time u drop teh oil