Bush replacement is a crucial step in maintaining the proper functioning of earth-moving machines, such as excavators, backhoes, drills, and lifters. There are various methods for installing a bush, each with its own advantages and disadvantages. Let’s examine the most common methods. Here you can find our tutorial video on YouTube.
Bushing press fit: Hydraulic Press
This method uses the force of a hydraulic press to insert the bush into its seat. It’s crucial that the press is correctly aligned with the bush and seat. Misalignment can cause damage to the bush or the seat. Moreover, the applied pressure must be adequate for the task. Excessive pressure can cause ovalization and deformation, while insufficient pressure might not allow for correct installation.
Mounting Bushings Without a Press: The Liquid Nitrogen Method
The liquid nitrogen assembly method takes advantage of thermal contraction. The bush is cooled with liquid nitrogen, causing it to shrink. Once cooled, the bush is inserted into its seat. As the bush warms up, it expands, ensuring a perfect fit. It’s important to remember that liquid nitrogen must be handled with care and can cause severe cold burns if it comes into contact with the skin. Therefore, it’s essential to wear gloves and protective glasses when handling this liquid. Also, once the bush has been cooled, it should be installed as quickly as possible. If the bush is allowed to warm up before installation, it may not fit properly. Finally, after installation, the bush should be left to warm up evenly at room temperature.
Bushing press fit: Hammer
Although this is the simplest method, it’s also the least recommended, in fact, we strongly advise against it. Using a hammer to install the bush can easily lead to deformations of both the bush and the seat. This method should be avoided if possible, as it’s imprecise and overly approximate.