Drive shafts and joints

Drive Shafts

The drive shaft is an essential part of a vehicle’s driveline and is responsible for delivering torque from the engine to the wheels.
It’s a mechanically rotating tube that transfers the rotation from the transmission to the different gears and then onto the wheels.
Drive shafts are usually found in rear-wheel drive vehicles, but they can also be seen in four-wheel drive and front-wheel drive vehicles when they are long enough to reach from front to rear.
There are two types of drive shafts: single-piece drive shafts and two-piece drive shafts. Single-piece drive shafts are lighter and cheaper but they cannot accommodate large angles or lengths. Two-piece drive shafts are used in long vehicles to overcome the length problem and to minimise the shaft’s bending.

U-Joints & CV Joints

The universal joint (U-joint) is a coupling that connects rigid rods which are inclined to each other, and it’s used in drive shafts in order to allow the shaft to flex or “bend” in any direction.
U-joints need to be greased regularly to reduce friction and wear.
A constant velocity joint (CV joint) is a special type of universal joint that’s designed to handle greater angle manipulations. It’s commonly found in front-wheel drive and all-wheel drive vehicles.
CV joints are packed with grease and sealed with rubber or plastic boots. The grease keeps the joint lubricated, and the boot keeps dust and dirt out.
An issue with CV joints is that if the boot gets damaged, the grease can leak out and particles can get in, causing wear and potentially leading to joint failure.

Driveline Vibrations

Driveline vibrations are generally caused by damaged or worn out components of the drive shafts or joints.
Common symptoms of driveline vibration include intense shaking underneath the vehicle, unusual noises, difficulties turning, or vibrations that increase with speed.
Fixing driveline vibrations often involves replacing or repairing shafts or joints that may have been damaged or worn out.