The fault diagnosis and troubleshooting methods of the cross shaft universal coupling are as follows:

(1) First, check whether the connecting bolts of the universal joint flange are loose, and tighten them as appropriate.

(2) If the fault is still eliminated, remove the drive shaft assembly and perform a balance test on a balancing machine. If the unbalance is very poor, balance compensation should be performed.

(3) If the abnormal noise and vibration are still eliminated, check whether the expansion joint is installed to the standard mark. If the installation is correct, support the car body and start the engine to run at low idle speed. If the universal coupling swings Large, it can be used to measure the deflection position, direction and amount of deflection with a scribing needle. If the two ends of the drive shaft are not straight or bent, a soft metal that matches the shaft tube should be cushioned on the pressure strip for cold pressure correction.

(4) If the noise is not caused by the above reasons, check whether the universal joint shaft tube has bumps and depressions, and whether the balance sheet is missing.Loss of the balance sheet requires re-welding the same balance sheet at the original solder joint position.If the universal joint shaft tube has obvious depressions and the universal joint itself loses balance, the spline shaft and universal joint fork should be cut off on the lathe, and a shaft tube with a larger diameter than the inner diameter of the shaft tube should be inserted into the shaft tube. The thin mandrel is repaired by hammering in the depression.Then the cut spline shaft and universal coupling are cross-welded to the original position.In order to ensure the quality of repair, the shaft tube should be placed on a special bracket when welding, and the number of points should be symmetrically spot welded on the circumference, and then the deflection should be corrected, and after correction, welded along the circumference.After cooling down after welding.Check again, and re-welding should be done if the swing difference is too large.The process is more complicated.If the universal joint is dented and damaged in a large area, the drive shaft of this section needs to be replaced.