How to Determine the Belt Tension Standard?
2 Answers
The belt tension can be roughly judged by hand pressing, and the inspection method is very simple. First, check the belt tension by pressing firmly with your thumb on the belt between the two pulleys. The pressing force should be about 10kg. If the belt deflection is about 15mm, the belt tension is considered just right. If the deflection is too large, the belt tension is considered insufficient. Additional information: 1. Belt function: Due to its elasticity, the belt can cushion impacts, reduce vibrations, and ensure smooth transmission, but it cannot maintain a strict transmission ratio (the ratio of the driving pulley's revolutions per minute to the driven pulley's revolutions per minute). When encountering obstacles or overload, the belt will slip on the pulley, thus preventing damage to the machinery. 2. Belt adjustment: Belt transmission is simple, cost-effective, easy to maintain, and convenient to replace. However, due to belt slippage on the pulley, the mechanical efficiency of belt transmission is low, and the belt itself has poor durability. Over time, it will gradually stretch, so it should be adjusted regularly.
I've been driving for over 30 years and know a thing or two about belt tension. The standard is basically getting the belt tension just right. The simplest method is manual pressing: at engine idle, use your thumb to press down on the middle of the longest section—there should be about 1 cm of deflection for proper tension. Too loose and the belt will slip, wear out faster, and may affect the water pump or alternator; too tight will cause premature failure of bearings and the belt itself. I recommend checking every 10,000 km, especially when old belts show cracks—extra caution is needed. Consulting the vehicle manual is the most reliable approach, as standards vary by model. Beginners shouldn't adjust blindly; it's safer to visit a professional shop for a tension gauge measurement.
