Pull the motor apart, grease the armature, put it back together. Make sure to move the brush springs up to the loading position and push the brushes to the retracted position when loading the armature through the brush housing. Order of assembly is armature to brush housing, then assembly that subassembly to motor housing, than that to gearbox. Lube worm gear before going in to gearbox. You may have to use allen wrench to help fully seat worm gear by turning center of main gear.