• The ATV World

FIX-IT: How-To grease ball joints and A-arm bushings

In the earlier days of the ATV, most A-arms and ball joints didn’t come with an ability to quickly maintain and grease the parts. Over time, grease will get old, slowly seep out of bushings and ball joints or get contaminated. When this happens, your parts become a lot more fragile and effect the handling and steering of your ATV or UTV. It is more common for modern components to come with Zerk fittings that allow you to hook up a grease gun and quickly lubricate the components. A lot of aftermarket companies make A-arms and ball joints that include Zerk fittings on their components. Here is a simple how-to on using a grease gun on Zerk fittings.


A Zerk grease fitting works like a one-way valve. There is a spring inside the mechanism that keeps constant pressure on the ball at the tip of the fitting. This doesn’t allow grease to escape the components, however when you connect a grease gun to the Zerk fitting and start pumping the lubricant into it, the ball will depress into the fitting via applied pressure.

Sometimes, the ball will not depress and allow grease to enter into the mechanism. If that is the case, you should replace the Zerk fitting. Simply unthread it and thread in a new one.


First step is to obtain a grease gun. The one we have here works well, however it would be better to purchase one with a flexible tube to help get to the hard to reach fittings. Make sure you purchase the correct type of grease to lubricate the parts. Your ATV and UTV dealer should be helpful with that information. The way grease works is that it creates a slippery film that prevents the parts from touching. If you get grease that is too thin it may not have the film strength to prevent friction between the parts, and then you get wear.

Next, locate the Zerk fittings and inspect the parts that need greasing. Make sure you clean off the Zerk fittings and any other dirt and grease on the components. The Grease gun needs a clean surface to mate to on the fitting. If you do not thoroughly clean the fitting, you could get debris stuck in it which will cause damage to internal parts or keep the fitting from closing.

Once everything is clean, you can connect the grease gun to the fitting. You should feel the gun lock itself onto the fitting. Now you can start pumping grease into your components. If grease immediately starts coming out of the gun onto your machines ball joints or A-arms then the Zerk fitting is not operating properly.

You should be able to get a few pumps of grease into the Zerk fitting before it starts spilling out of the tip of the gun. Once grease has filled the component you are maintaining, it will leak out of the gun onto the fitting instead of in it. Once this occurs, you can remove the grease gun and the component you are lubricating will be full.

When filling ball joints with grease, make sure you inspect the ball joint boot for rips or tears. If visually you don’t see either, then you can go ahead with introducing grease. Once you start filling a ball joint, if grease starts coming out of the boot then it is best to replace the ball joint. The same goes with an A-arm bushing. If grease seeps out of the seals then the bushing is bad and should be replaced. That is why it is important to inspect and clean components before you begin to maintain them.

© 2014-2020 by Eric Kuchenbrod

The ATV World

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