When a loader makes a “clunking” noise, body vibration during starting, gear shifting, or load changes, it is often related to the drive shaft universal joint, main reducer bevel gear, or differential. The transmission system is the bridge that transfers power from the engine and gearbox to the drive axle.

A universal joint, also called a cross joint or Cardan joint, connects the drive shaft to the transmission and drive axle. Because the drive shaft has an angle, the universal joint produces a non-constant velocity characteristic during rotation. Therefore, double universal joints, constant velocity joints, or reasonable phase arrangement are often used to reduce vibration. On the LIANYU Global product page, the 860116585 Universal Joint and Cardan Joint are suitable for the XCMG loader ZL50GN. The 275100167 Spiral Drive Axle Bevel Gear is suitable for the LW188, LW300, and LW500. The 275101678 Front and Rear Main Reducer is suitable for models such as the ZL50G.

Common causes of transmission noise include worn universal joint cross shafts, lack of lubrication in needle roller bearings, bent drive shafts or fallen balance weights, excessive meshing clearance of main reducer bevel gears, and loose differential bearings. Symptoms include noise during starting, high-speed vibration, and jerking when releasing the accelerator. During maintenance, regularly grease the universal joints, check whether the dust boots are cracked, confirm drive shaft bolt torque, and avoid rough starting and overload operation. If the noise comes from inside the drive axle, check the bevel gear contact pattern and backlash, and replace the bevel gears in pairs if necessary.