Speedo, speedo, speedo; my on-going adventure. Today maintaining 80mph, I noticed the needle dropping, then holding at 30mph, while still doing 80. I reach behind the gauge, rattle the cable, no change. I then reach down to the trans angle drive and bingo, it's been backed out a bit, on it's own. I screw it back down and all is well. A little lock-tight or similar will be applied tonight when I get home!