Jaw crusher is the core primary crushing equipment in all stone aggregate, mining ore and construction waste production lines. It undertakes the first coarse crushing process to break large raw rocks into medium-size materials for secondary cone or impact crushers. During long-term continuous operation, improper feeding, irregular maintenance and component wear will trigger various faults, lowering output and delaying production.
This professional troubleshooting guide summarizes the most frequent jaw crusher malfunctions encountered by global quarry customers, analyzes real root causes and provides safe, operable solutions based on industrial operation standards. All solutions are verified by UNIQUEMAC after-sales engineers with thousands of on-site service cases.
Jaw crusher serves as the primary coarse crushing host at the front of the complete production flow. Large raw stones from blasting or excavation are sent into the jaw crusher via vibrating feeder. After compression crushing, medium-sized semi-finished materials are transported to cone crusher, impact crusher or mobile screening equipment for secondary fine crushing and grading. Without stable jaw crusher performance, the whole assembly line will face feeding shortage and low finished aggregate yield.
𝐑𝐨𝐨𝐭 𝐂𝐚𝐮𝐬𝐞𝐬
Uneven unilateral feeding leads to unbalanced load inside the crushing cavity;
Anchor bolts of base frame are loose after long running;
Eccentric shaft bearings are lack of lubrication or severely worn;
Jaw plate fixing bolts fall off and cause metal collision;
Vibration damping rubber pads aging or missing.
𝐏𝐫𝐚𝐜𝐭𝐢𝐜𝐚𝐥 𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬
Adopt full-section uniform feeding by vibrating feeder, avoid concentrated material dumping on one side;
Stop the machine regularly to retighten all foundation and jaw plate bolts;
Refill special high-temperature grease for bearings every 8 working hours; replace damaged bearings immediately;
Add new anti-vibration rubber pads at the bottom of crusher frame;
UNIQUEMAC jaw crushers adopt precise dynamic balance design. Matching damping accessories can absorb most vibration to meet industrial noise standards under standard installation and maintenance.
𝐑𝐨𝐨𝐭 𝐂𝐚𝐮𝐬𝐞𝐬
Fixed/movable jaw plates wear unevenly with partial tooth loss;
Raw materials pile on one side of crushing chamber, incomplete compression;
Discharge gap (CSS) adjusted too big or inconsistent;
Toggle plate wear affects crushing stroke stability.
𝐓𝐫𝐨𝐮𝐛𝐥𝐞𝐬𝐡𝐨𝐨𝐭𝐢𝐧𝐠 𝐒𝐭𝐞𝐩𝐬
Shut down the equipment to inspect jaw plates; replace severely worn jaw dies in pairs;
Optimize feeder layout to realize full-chamber uniform material distribution;
Recalibrate the discharge opening according to required finished size; keep consistent gap on both sides;
Check toggle plate and toggle seat regularly, replace worn support components;
Carry out daily visual inspection of finished aggregate to adjust parameters in advance.
𝐓𝐫𝐢𝐠𝐠𝐞𝐫 𝐅𝐚𝐜𝐭𝐨𝐫𝐬
Too much continuous feeding blocks the discharge port;
Hard uncrushable objects (steel bars, iron blocks) enter crushing cavity;
Drive V-belts loose or slipping, insufficient transmission power;
Factory input voltage unstable or too low;
Discharge chute blocked by sticky wet materials.
𝐒𝐭𝐚𝐧𝐝𝐚𝐫𝐝 𝐄𝐦𝐞𝐫𝐠𝐞𝐧𝐜𝐲 𝐇𝐚𝐧𝐝𝐥𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬
Cut off the total power supply first to avoid accidental startup;
Use professional tools to clean all accumulated materials and foreign metal inside crushing chamber;
Check belt tightness; tension loose belts or replace aged cracked belts;
Test workshop voltage; configure stable voltage transformer if voltage fluctuation exists;
Dry high-humidity raw stones in advance to reduce sticky blockage risk;
If repeated stalling happens after above operations, contact UNIQUEMAC after-sales team for on-site inspection.
𝐂𝐚𝐮𝐬𝐞𝐬
Maximum feed size exceeds the crusher’s allowable feeding opening;
Jaw plates seriously worn, compression force declines;
Feeder running speed too slow, insufficient material supply;
Discharge gap set too small leading to repeated circulation inside cavity.
𝐅𝐢𝐱𝐞𝐬
Pre-screen oversized blocks before feeding to control maximum feed dimension;
Timely renew manganese jaw plates to guarantee crushing force;
Adjust vibrating feeder frequency to match jaw crusher processing capacity;
Appropriately enlarge discharge gap within finished grain requirements.
𝐂𝐚𝐮𝐬𝐞𝐬
Excessive or insufficient grease filling in bearing chamber;
Wrong model lubricant with poor high-temperature resistance;
Dust and mud invade bearing seat and cause abrasion.
𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬
Clean old grease completely before refilling; follow the recommended filling volume;
Use high-temperature anti-wear grease designated by UNIQUEMAC;
Replace bearing sealing rings regularly to prevent dust ingress; pause production once bearing temperature exceeds 90℃.
𝐂𝐚𝐮𝐬𝐞𝐬
Belt tension too tight or too loose;
Pulley groove worn and deformed;
Stone fragments fall between multiple belts and cause friction damage.
𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬
Adjust pulley distance to get standard belt tightness;
Repair or replace worn pulleys;
Install protective baffle to stop stone splashing onto drive belts.
Daily Preventive Maintenance Tips to Reduce Jaw Crusher Failures
Lubricate eccentric shaft bearings and toggle seats every shift;
Tighten all connecting bolts before startup each day;
Remove iron sundries via magnetic separator before materials enter crushing chamber;
Stop feeding first then turn off the machine after daily work, empty the crushing cavity;
Store spare jaw plates, belts and bearings for quick replacement;
Carry out full machine inspection every 30 working days.
Most jaw crusher failures stem from irregular feeding and neglected daily maintenance. Operators can quickly judge faults and solve minor problems by following this troubleshooting guide to cut downtime and maintenance costs. If you encounter complex mechanical failures or need customized jaw crusher models for your quarry project, UNIQUEMAC’s global after-sales team provides 24-hour remote technical guidance and overseas on-site service support.
