What are the causes of a broken car driveshaft?
2 Answers
There are several reasons for driveshaft fracture or detachment: 1. The dynamic balance of the driveshaft assembly exceeds standard specifications: driveshaft deformation, balance patch detachment, bearing cover balance shim asymmetry, etc. 2. Loose or damaged driveshaft connecting bolts: improper driveshaft assembly, failure to tighten the four flange bolts according to specified torque, or thread stripping of certain screws, lack of grease or improper lubrication of cross bearings, etc. 3. Improper maintenance: failure to strictly follow repair process procedures during maintenance operations, random hammering causing driveshaft component deformation. 4. Improper driving operation: subjecting the driveshaft to extreme impacts leading to component damage.
I've been driving heavy trucks for long-distance hauling for over 20 years and have experienced several driveshaft breakages. The most common cause is metal fatigue—hauling heavy loads all day on bumpy roads causes repeated twisting at the shaft joints, which gradually cracks and eventually breaks. Overloading is another major factor; when the cargo is too heavy, the starting torque becomes excessive, and the shaft can snap instantly. Poor materials or manufacturing defects can also lead to premature failure, such as weak welding or rust corrosion, especially after driving through mountain roads and soaking in water puddles. Once it breaks, the truck becomes completely immobile, requiring a tow and major repairs. My advice is not to skimp on regular maintenance—apply grease periodically, check for wear and tear, and avoid sudden acceleration when fully loaded. Good preventive measures can save a lot of trouble.
