@andrew leroy @Michael G Thank you both for your help! I tried following your instruction but didn't manage to get take the lead screw out without completely removing the eccentric guides. HOWEVER! I managed to get it working smoothly through the whole Z-Axis length! Could just be luck but I did following: 1) Slightly loosen the 3 screws holding the lead screw nut. Only by a tiny amount to allow for the smallest amount of wiggle 2) Reverted back to an three eccentric guides and one fixed guide on the gantry to allow for a better adjustment 3) Use a lot of lube on the rubber cap at the top of the lead screw 4) Lower the gantry down until the print head touches the bed (I had the hot end rubber sock on just it case) 5) Adjust the 3 eccentric guides until there's only a slight wobble, and the gantry will slightly gets stuck when lowering but easily falls down when wiggle the far end of the gantry. 6) Stop the lead screw from moving whilst push down lead screw top bracket in place. This should stop the stutter as suggested by @Makertech 's comment 7) Did further adjustments on the eccentric guides until I was happy with the lack wobble and smooth motion I did notice that lowering the gantry down by hand could sometimes cause the top of the lead screw to slip from the top bracket but this didn't happen when I used the pronterface to move the gantry down. I might redesign the top bracket to add a lip to stop the lead screw from completely slipping out.

Thank you for the reply @Michael G but I don't think the link is working 🤔