Apparatus for repair and renovation of crankshaft journal surfaces, said apparatus comprising a laser nozzle, and characterized by the following features: - two guide-ways and two opposite-guide-ways for positioning said apparatus on crankshafts fillets; - two frame parts where each frame part is fixed to respectively guide-way; - at least two upper rods by means of which both frame parts are in fixed connection to each other, wherein the upper rods are positionned in the upper part of the frame part; - at least two lower rods by means of which both frame parts are in fixed connection to each other, wherein the lower rods are positionned in the lower part of the frame part; - two carriages (7A; 7B) which are installed on the upper rods and the lower rods so that the carriages (7A; 7B) can be slidably moved along said rods (5, 6); - the laser nozzle is installed on the carriages (7A; 7B); - two control motors (8A; 8B), wherein a first control motor is installed in the first carriage and operatively connected to the laser nozzle to control its pivoting angle, and a second control motor is installed in the second carriage and operatively connected to the one of the two lower rods by means of a gearing transmission to control a longitudinal position of the laser nozzle; two supporting plates where each supporting plate is fixed to respectively opposite-guide-way; - at least two opposite-rods by means of which both supporting plates are in fixed connection to each other, wherein the opposite-rods are position in the opposite-guide-ways; - four adjustable arms by means of which guide-ways and opposite-guide-ways are fixed slidably on the crankshaft journal fillets; - at least four screws by means of which angle and position of the adjustable arms is fixed; - at least eight guidance-screws by means of which adjustable arms are connected to the guide-ways and opposite-guide-ways; and by means of which also eight expandable-shrinkable elements are rotatably connected to the guide-ways and opposite-guide-ways; - at least eight expandable-shrinkable elements by means of which laser nozzle top-down centre position is ensured towards crankshaft fillet; - at least four side plates, fixed on the engine housing service hatches bolts, by means of which expandable-shrinkable elements are connected to the engine housing; - at least eight guidance-bolts fixed to the side plates allowing rotatable connection of the expandable-shrinkable elements. - two guide-ways and two opposite-guide-ways for positioning said apparatus on crankshafts fillets; - two frame parts where each frame part is fixed to respectively guide-way; - at least two upper rods by means of which both frame parts are in fixed connection to each other, wherein the upper rods are positionned in the upper part of the frame part; - at least two lower rods by means of which both frame parts are in fixed connection to each other, wherein the lower rods are positionned in the lower part of the frame part; - two carriages (7A; 7B) which are installed on the upper rods and the lower rods so that the carriages (7A; 7B) can be slidably moved along said rods (5, 6); - the laser nozzle is installed on the carriages (7A; 7B); - two control motors (8A; 8B), wherein a first control motor is installed in the first carriage and operatively connected to the laser nozzle to control its pivoting angle, and a second control motor is installed in the second carriage and operatively connected to the one of the two lower rods by means of a gearing transmission to control a longitudinal position of the laser nozzle; two supporting plates where each supporting plate is fixed to respectively opposite-guide-way; - at least two opposite-rods by means of which both supporting plates are in fixed connection to each other, wherein the opposite-rods are position in the opposite-guide-ways; - four adjustable arms by means of which guide-ways and opposite-guide-ways are fixed slidably on the crankshaft journal fillets; - at least four screws by means of which angle and position of the adjustable arms is fixed; - at least eight guidance-screws by means of which adjustable arms are connected to the guide-ways and opposite-guide-ways; and by means of which also eight expandable-shrinkable elements are rotatably connected to the guide-ways and opposite-guide-ways; - at least eight expandable-shrinkable elements by means of which laser nozzle top-down centre position is ensured towards crankshaft fillet; - at least four side plates, fixed on the engine housing service hatches bolts, by means of which expandable-shrinkable elements are connected to the engine housing; - at least eight guidance-bolts fixed to the side plates allowing rotatable connection of the expandable-shrinkable elements.