What is the Slip Joint in Propeller Shaft in Transmission System

The slip joint in propeller shaft is the upgraded version of the Universal Joint. The slip joint in the propeller shaft connects the transmission and the propeller shaft in a single unit. The slip joint is used in the system to transmit the torque in the direction it fits. In this article, I will discuss the benefits and the details of the Slip Joint.


Slip Joint in Propeller Shaft

The propeller shaft connects the transmission main shaft and the differential pinion shaft. It is to be noted here that the engine and the transmission are more or less rigidly attached to the car frame. The rear axle housing, with wheels and differential, is attached to the frame by springs. As the rear wheel encounters irregularities in the road, the springs compress or expand.

The differential, with rear axle housing and wheel, moves up and down. This not only changes the angle of drive but also changes the length of the propeller shaft—the universal joint permits variation in the angle of drive. The slip joint permits the effective length of the propeller shaft to change. Suppose there is no slip joint. the propeller shaft would buckle or break.

Read more- What is the Function and the Working of the Planetary Gearbox?

In the exhaust system, the slip joint is also used to connect various sections of the exhaust pipes and components like the muffler. These joints allow for a small degree of movement, which helps to compensate for thermal expansion and contraction of the exhaust system as it heats up during operation and cools down when the engine is turned off.

Working of Slip Joint in Propeller Shaft


When the rear springs compress, the differential rises and the propeller shaft is shortened. When the springs again expand, the differential returns to its original position and the propeller shaft gets its original length. Therefore, a slip joint is used in the transmission system to compensate for the change in length of the propeller shaft.

In some vehicles using Hotchkiss drive, the slip joint lies between the propeller shaft and the universal joint connecting the propeller shaft with the transmission main shaft. In some vehicles, the slip joint lies between the transmission main shaft and the universal joint. In cars provided with a torque tube drive, a slip joint is not always necessary.

The slip joint provides flexibility, preventing these problems. For example, when you accelerate or the suspension compresses, the propeller shaft can temporarily lengthen to accommodate the changes. Over time, the splined components of the slip joint may wear out, leading to drivetrain issues. Regular inspection and maintenance are necessary to ensure that the slip joint functions correctly. Lubrication may be required to reduce friction and wear.

Construction of Slip Joint

A slip joint consists of outside splines on one shaft and matching internal splines on the mating hollow shaft. The splines cause the two shafts to rotate together as well as to permit them to move endwise. This compensates for any change in the length of the propeller shaft so the rear axles move toward or away from the car frame.

Read more- Know these 10 Tips to Sell Your Car Online with Perfection

The key to the slip joint’s construction is the sliding mechanism, which allows the two sections of the shaft to slide in and out of each other. This sliding is typically achieved through splines. Splines are grooves and ridges that mesh together, allowing for the telescoping motion. One section of the shaft will have splines (grooves), and the other will have mating ridges that fit into these grooves.

Some slip joints have a locking mechanism to secure the sliding sections of the shaft in place, preventing unintended movement. This locking mechanism can be in the form of a locking collar or other retention features.

Advantages of Slip Joint

Nowadays the slip joint is very much popular in the automobile sector. The advantages that make the slip joint a suitable option are-

  1. Slip joints can accommodate minor misalignments between connected components, reducing the need for precise alignment during assembly.
  2. Slip joints can act as a buffer against vibrations and shock loads.
  3. When subjected to excessive loads or torque, slip joints can slip or disengage, preventing damage to the connected components.
  4. In applications where temperature variations cause expansion and contraction of components, slip joints allow for this movement without causing stress or binding.
  5. Slip joints can make it easier to disassemble and service power transmission components.
  6. By reducing the transmission of vibrations and impacts, slip joints can help minimize noise generation in the system, resulting in a quieter and smoother operation.
  7. Slip joints are versatile and can be used in a wide range of power transmission applications, from automotive drivetrains to industrial machinery, depending on the specific needs of the system.


A slip joint is designed to provide flexibility in the driveshaft, allowing it to expand or contract within the limits of the sliding mechanism. This flexibility accommodates changes in the distance between the transmission and the rear axle due to suspension travel, engine movement, and other factors.

Frequently Asked Questions(FAQ’S)

What is a slip joint in a vehicle’s driveshaft, and what is its purpose?

A slip joint in a vehicle’s driveshaft is a flexible coupling that allows for limited axial movement. Its primary purpose is to accommodate changes in the distance between the transmission and the rear axle, preventing drivetrain binding and vibrations.

What maintenance is required for a slip joint in a driveshaft?

Regular inspection and lubrication are necessary to ensure the slip joint functions correctly. Lubrication helps reduce friction and wear, while inspection ensures the seals and sliding mechanism are in good condition.

Can a slip joint eliminate drivetrain vibrations?

While slip joints help dampen vibrations, they may not eliminate all vibrations. Other factors, such as balancing, alignment, and the condition of drivetrain components, also affect the overall smoothness of the drivetrain.

Do slip joints wear out over time, and if so, how often should they be replaced?

Yes, slip joints can wear out over time due to factors like friction and use. Replacement frequency depends on various factors, including the vehicle’s mileage and operating conditions. Regular inspections can help determine when replacement is necessary.

If you like the article “What is the Slip Joint in Propeller Shaft in Transmission System”, then please do share.

Spread the love

1 thought on “What is the Slip Joint in Propeller Shaft in Transmission System”

Leave a comment