As with the x-axis, I found the adjustment/clamping mechanism for the y belt to be a bit of a pain as well. Requires: 11x 3.8mm M3x0.5 threaded heatset inserts (10 for t-track/sliders, one for endstop actuator) 6x M3 x 10mm socket head cap screws (4 for clamps, 2 for set screws which hold sliders in place on t-track) 3x M3 x 6mm socket head cap screws (to mount t-track) 1x M3 x 50mm socket head cap screw (for adjustment) 7x M3 washers (clamps, t-track mounting screws) Don't forget that you will need the endstop actuator if you replace the original y belt mount. To adjust, loosen the set screw on each slider. Adjust tension using the 50mm screw, then re-tighten set screws to lock everything in position. Print at high (90-95%) infill for robust parts. Mine were made in ABS at 0.20mm layer height with 1 perimeter and 4 top and bottom shells, 95% infill.