The first failure phenomenon: the temperature rise of the rack bearing pedestal and movable jaw is excessive. Reasons: 1) there is too little or too much oil in the bearing of jaw crusher; (2) the oilhole is blocked so that the oil cannot be added in the bearing; (3) the counterweight of the sheaves and the rack beats deviate; (4) the axial shifting happens on the fixed lining; (5) bearing gets worn or the retainer get damaged; (6) the friction between the seal cartridge of the movable jaw and end cap causes temperature rise, but not the temperature rise of bearing, or the dual panel cover of the rack bearing pedestal rotates with the main axis. Remedies: 1) conducting timely and quantitative refueling as required by the instructions; (2) clean up the oilhole and tank; (3) adjusting the position of sheaves poise rightly; (4) Removing the bearing cover on the rack and locking firmly fixed bushing and removing the flywheel or sheaves, and replacing a new fixed bushing; (5) taking replacement of bearings; (6) Replacing the end cap and the seal cartridge or loosening the upper bearing cap on the end of the rack heating bearing pedestal and putting it into the rack bearing seat tank with cover inlay and fuse, then making the bearing cover fixed to avoid the rotation of the inlay cover. The second failure phenomenon: the rack cracks. Reasons: 1) casting defects or welding quality defects; (2) the use of substandard bracket and bracket pad, makes the rack crack when the crusher stands strong impact, but the breaking protection of the bracket does not occur; (3) the fixed jaw is not fixed and it traverse up and down for a long time, hitting the front wall plate of the rack tooth; (4) the two bolts on the bearing cover loosening rack; (5) the fixed and movable jaw plate are still used after the tooth profile get worn.2) Remedies: 1) Clearing the original crack defects and conducting welding correction, if necessary, replacing the new rack; (2) repairing or replacing the rack, and putting on the original braces and brackets pad; (3) repairing or replacing the new rack, and fixing tooth plate and bolts; (4) tightening the bolts on the bearing cap; (5) repairing or replacing the rack and timely replacing jaw plate after it get worn.