Hey Jac
So original GT40 have a UJ on the outboard end, which would put the phasing in 90 degree chunks
Next to the gearbox they had a rubber doughnut. From memory it had 3 bolt things through from each side giving a 60 degree phasing if I calculate it correctly.[[[ NO, due to being elastic this is considered to be a CV joint even though it is really like a torsional twist absorber for want of a better description.]]]
How does the phasing work so it is not jerking/vibrating?A single U-joint run at an angle & driven at constant speed on one shaft will induce an uneven rotating speed on the other side of the u-joint, that uneven rotating speed changes twice in each revolution and that uneven amount increases with u-joint angle increase. When you complte the shaft with the second u-joint the uneven rotational speed changes are canceled out on the outer shaft. However the uneven rotational speed still remains in that middle shaft at any time the angles remain, to further confuse things as shown in the video if th angles are not the same some difference in speed will be induced in all shafts and it depends which end of the shaft has the most resistance/weight attached to it as to where those forces will felt.
Perhaps angles are so minimal that it is not a problem
Cheers
Ian