Disassemble the used bearing from the shaft by using a press.
Disassemble the used outer bearing shell from the gearbox housing.
Install a new bearing into the pump shaft, by using a press. Remember to put the outer bearing shell onto the bearing, to protect it from being damaged by the press! After that, remove the outer shell from the bearing again.
Install the outer bearing shell into the gearbox.
Tighten rotor nuts slightly on the pump shafts, so the gearbox can be put securely on the table (on the shafts). From the rear side of the gearbox, the second set of bearing is installed on each shaft.
Heat up the bearings, so they would expand and can be installed on the pump shafts WITHOUT using a press (recommended).
Assemble the keys and gears onto the shafts. You can use a small piece of pipe to press the gears evenly onto the shafts.
When assembling the second gear, make sure that the key slots are parallel with one another and the teeth are well aligned.
Insert the fixing rings and tightening nuts from the back of the shafts. Tighten first by hand! After that, tighten with a special tool.
After each tightening, measure the required torque or resistance to turn the shafts (in Newton-meters). Please follow a special table for the torque values. Readjust by tightening/loosening until you get the correct torque.
Remember to knock the shaft lightly by a soft hammer from the back, in order to slightly loosen the bearings, before you measure the required torque.
After the bearings have been correctly tightened, secure the position of the tightening nuts, by bending one tooth of the fixing rings into the slot of the tightening nuts.
Do the same for the second shaft. Remember to measure the rotational resistance or torque on the first shaft again! Also remember to secure the tightening nut like for the first shaft.
Insert the oil-seal into the gearbox back cover. Use a small cylinder-shaped tool to help push the oil-seal evenly into the gearbox.
Insert the oil plug into the draining port.
Put the gearbox back cover onto the gearbox front casing.
Remember to align the back cover well, before you tighten the screws!
insert the front oil seals. Remember: the face showing the springs must be facing inside!