Okay so my 1978 280z has a 5 speed transmission (not sure what year), has always made noise in 1st and 2nd gear when not pressing on the throttle (kinda soundings a little like a grinding and maybe whining noise). When the clutch is pressed in, no noise, if I am on throttle, no noise. Only makes noise 1st and 2nd gear when coasting (no throttle applied) and you can kinda feel it not coasting smoothly but once again only in these two gears. Based on the symptoms and pictures I provided, are my be