Testing a useful tool

By the staff of Dirt Wheels

The Machined Integrations over-the-axle bearing greasing tool is a high-quality unit that is well-designed and -executed.


In the May 2019 issue of Dirt Wheels, we had a story on greasing UTV wheel bearings. Since then we have had experience with Machined Integrations, LLC (MI) bearing greasing tools. A quality, well-designed tool is always a pleasure.

And in the case of UTV and 4×4 quad wheel bearings, these tools are almost required. The bearings are sealed on both sides. The only opening for grease is the seam in the split inner race, so you would have to risk damaging the bearings or the seals to grease them by hand, and, of course, it would be a giant mess. With the MI bearing tools, the job is quick, easy, and clean. We serviced Polaris RZR S wheel bearings.

This split in the inner wheel-bearing race is the only way to get grease into the bearing easily. The MI tools are designed specifically for this task.

Removing the bearings is never required with the MI bearing tools, but on many machines, you have the option of not removing the axle. For the Polaris, MI has a normal greaser that requires pulling the knuckle off the axle or removing the axle.

It is the cheapest option at $29. MI also builds a tool that inserts over the axle. It is larger and more complex to machine and sells for $43. For those with shops or lots of riding buddies, there is a $115 Polaris 3-pack of over-the-axle tools that should cover any common Polaris machine.

The MI tool slips right over the axle and fills the inner diameter of the bearing. The O-rings are a snug fit going in and coming out, but it doesn’t require undue effort.


The greasers are machined from aluminum billet, assembled, and black-anodized. They are fitted with beefy O-rings to keep the job free from mess and wasted grease. For the front of our Polaris, we had to remove the wheel, remove the caliper, and pull the rotor and hub out. That allowed us to slide the tool over the axle and grease away.

We kept a finger on the tool to be sure, but we saw no tendency for the tool to back out of the bearing and leak grease. This is all of the mess that we had after greasing the bearing.

After the job, we used a single paper towel to wipe off the threaded-in grease fitting and the outside of the tool. The single grease fitting connects to four ports on the side of the tool.

There are O-rings on both sides of the ports. Between the O-ring grooves, the tool has a slight depression machined in for the grease to migrate easily around the tool. We wiped that off as well. That was all the mess for what is usually a nasty job—one paper towel.

Since there are four ports and the grease channel, the entire bearing is greased at once. There is no reason to rotate the tool.

MI’s standard-bearing greasing tool is smaller, and it is easier to make, so it is cheaper. It requires pulling the knuckle away from the axle or removing the axle. The bearing is out for illustration purposes. There is no need to remove the bearing.


Buying the tools is easy, and they are available for an astonishing number of machines. Some machines have too little clearance between the axle and the knuckle, so the over-the-axle option is not available for those machines.

You can give Machined Integrations a call at (603) 420-8871 to order. You can buy online as well. Go to and click on the ATV/UTV products tab on the upper-right bar. That will jump you to the site, or you can go directly to that site. When you click on “Buy Now,” it will jump to another page. Click on
. That will allow you to see all of MI’s products and make a secure purchase.

The tools leave virtually no mess in the bearing or on the knuckle, but the tool does end up with a little grease that needs to be wiped away.


Until you use this tool, you cannot imagine how easy it can be to service bearings. They fit perfectly, work as advertised, and don’t make a mess.

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