A filler assembly for a gearbox having a housing and a port disposed within the housing, the filler assembly comprising: a cylindrical insert configured to be attached to an interior of the port, the cylindrical insert having a first insert end configured to be disposed within the port, a second insert end configured to extend outward from the port and configured to receive a detachable filler cap, a retaining lip around at least a portion of a first interior circumference of the cylindrical insert located at the first insert end, and a retaining slot around at least a second interior circumference of the cylindrical insert between the retaining lip and the second insert end; a retaining ring detachably coupled within the retaining slot; and a cylindrical baffle detachably retained between the retaining ring and the retaining lip, the cylindrical baffle comprising: a first baffle end having two or more first openings and a second baffle end having two or more second openings, wherein each first opening is offset from the two or more second openings, and one or more passageways connect the two or more first openings to the two or more second openings, and wherein the two or more first openings and the two or more second openings are sized and positioned to allow a lubricant to flow into the gearbox and at least in part prevent the lubricant from splashing out of the gearbox; or a first disk having the two or more first openings (326a, 326b, 326c); and a second disk having the two or more second openings (326d, 326e, 326f), wherein the two or more first openings (326a, 326b, 326c) are offset from the two or more second openings (326d, 326e, 326f); and wherein the second disk is attached to the first disk such that a gap is formed between one or more portions of the first disk and the second disk, and the gap connects the two or more first openings (326a, 326b, 326c) to the two or more second openings (326d, 326e, 326f). a cylindrical insert configured to be attached to an interior of the port, the cylindrical insert having a first insert end configured to be disposed within the port, a second insert end configured to extend outward from the port and configured to receive a detachable filler cap, a retaining lip around at least a portion of a first interior circumference of the cylindrical insert located at the first insert end, and a retaining slot around at least a second interior circumference of the cylindrical insert between the retaining lip and the second insert end; a retaining ring detachably coupled within the retaining slot; and a cylindrical baffle detachably retained between the retaining ring and the retaining lip, the cylindrical baffle comprising: a first baffle end having two or more first openings and a second baffle end having two or more second openings, wherein each first opening is offset from the two or more second openings, and one or more passageways connect the two or more first openings to the two or more second openings, and wherein the two or more first openings and the two or more second openings are sized and positioned to allow a lubricant to flow into the gearbox and at least in part prevent the lubricant from splashing out of the gearbox; or a first disk having the two or more first openings (326a, 326b, 326c); and a second disk having the two or more second openings (326d, 326e, 326f), wherein the two or more first openings (326a, 326b, 326c) are offset from the two or more second openings (326d, 326e, 326f); and wherein the second disk is attached to the first disk such that a gap is formed between one or more portions of the first disk and the second disk, and the gap connects the two or more first openings (326a, 326b, 326c) to the two or more second openings (326d, 326e, 326f). a first baffle end having two or more first openings and a second baffle end having two or more second openings, wherein each first opening is offset from the two or more second openings, and one or more passageways connect the two or more first openings to the two or more second openings, and wherein the two or more first openings and the two or more second openings are sized and positioned to allow a lubricant to flow into the gearbox and at least in part prevent the lubricant from splashing out of the gearbox; or a first disk having the two or more first openings (326a, 326b, 326c); and a second disk having the two or more second openings (326d, 326e, 326f), wherein the two or more first openings (326a, 326b, 326c) are offset from the two or more second openings (326d, 326e, 326f); and wherein the second disk is attached to the first disk such that a gap is formed between one or more portions of the first disk and the second disk, and the gap connects the two or more first openings (326a, 326b, 326c) to the two or more second openings (326d, 326e, 326f).