Originally Posted by xenon
+1, The half shafts / diff / prop / gearbox output are about the only bits left that are consistently involved in all the scenarios you mention.
Maybe a half shaft issue though, as that is slower than the prop and off centre would more likely cause a fore and aft rocking?
As the diff ratio is about 3.5:1 the prop shaft will be spinning 3.5 times faster than the wheels....
At 20mph, about 8m/s =
wheels / half shafts / hubs / diff input etc about 4 revs per sec
prop / gearbox output about 14 revs per sec