The driveshaft hanger is a key support component in the automotive transmission system. Its primary function is to secure the driveshaft and maintain its stability, ensuring smooth and reliable power transmission. The following is a detailed explanation of the driveshaft hanger:

1. Core Function
Support and Positioning
The driveshaft hanger, with its built-in double ball bearings and bearing seats, supports the center of the driveshaft, preventing excessive vibration or deflection caused by high-speed rotation or road roughness. For example, in a truck, the hanger is located on the center cross member of the frame, ensuring the fixed rotation of the front and rear driveshafts while allowing for slight oscillation and axial play of the front driveshaft.
Reducing Wear and Noise
The hanger's built-in rubber cushioning structure (such as an apron) effectively absorbs impact during driving, protecting the axle bearing and transmission output, and extending the life of the transmission system. Aging or damage to the rubber can cause unusual noise and vibration, potentially affecting driving safety.
Dynamic Balance
The driveshaft is a high-speed, low-support rotating component, making dynamic balance crucial. The hanger provides stable support, reducing axial runout during operation and preventing the risk of vehicle loss of control due to poor dynamic balance.

II. Structure and Materials
Components
A driveshaft hanger typically consists of a metal bracket, bearings, and rubber bushings. The metal bracket provides rigid support, the bearings ensure smooth rotation of the driveshaft, and the rubber bushings absorb vibration.
Material Selection
Metal: Mostly made of malleable cast iron or steel, which offers corrosion resistance and high-temperature resistance.
Rubber: Made of natural rubber, which exhibits moderate elasticity and resists cracking and aging. It is bonded to the metal bracket with a matching adhesive to prevent debonding.
Design Differences
Small cars: Due to the short distance between the transmission mainshaft and the rear axle reducer, a driveshaft hanger is typically not used.
Trucks: Due to the long distance between the driveshaft and the driven shaft, a central hanger is required. This hanger may be bolted into a crossmember or mounted below the crossmember.

III. Applicable Vehicles
Vehicle Compatibility
Driveshaft hangers are primarily used in front-engine, rear-wheel-drive vehicles (such as heavy-duty trucks and mid-size trucks), as well as some vehicles requiring long-distance power transmission (such as 4.2-meter trucks). For example, mainstream light trucks such as the Dongfeng 140, Dolica, and JAC Weiling are all equipped with these components.

Operating Requirements

In conditions of frequent starts and stops, heavy loads, or bumpy roads (such as urban delivery and short-distance transport), the performance of the hanger directly impacts ride smoothness and maintenance costs. A high-quality hanger can significantly reduce chassis vibration and improve ride comfort.

IV. Maintenance and Replacement

Fault Symptoms

Damage to the hanger bearing: Lack of grease leads to increased wear, or looseness between the bearing outer diameter and the seat.

Damage to the drive shaft: Deformation of the flange yoke and universal joint yoke can cause axis runout.

Material Defects: Improper casting can lead to metal porosity, air holes, or brittle cracks.

Replacement Tips

Model Compatibility: Select a hanger that matches the vehicle's specifications to avoid vibration caused by incompatibility.

Installation Specifications: Tighten bolts evenly to prevent pressure concentration caused by tilting of the hanger or cover.

Dynamic Balancing Test: After replacement, the drive shaft must be dynamically balanced to ensure smooth operation.