How To Grease A Bearing With A Grease Gun? A Fast and Easy Guide

How To Grease A Bearing With A Grease Gun

As you already know, a grease gun is used for applying grease to different metal parts to aid lubrication. One area that is difficult to access is a bearing. It is difficult to manually apply grease to a bearing. That’s why you need to know how to grease a bearing with a grease gun.

That’s what this article is about. In addition, there are answers to some frequently asked questions about greasing a bearing. The article is only a 7-minute read. Take the time to read it through to the end. Let’s get straight to business right away. 

How To Grease a Bearing with a Grease Gun? 6 Easy Steps

Step 1:

Remove the rubber seal that covers the balls in a ball bearing. You don’t have to remove the rubber seals on both sides. You only need to remove only one of the seals. Once you grease the balls, it will get to the other parts.

Step 2:

Install an injector needle to the mouth of your grease gun. 

Step 3:

Place the mouth of the needle on the balls in the bearing. Squeeze the trigger or pull the lever to dispense grease. 

Step 4:

Manually rotate the bearing as you dispense grease on the bearing. 

Step 5:

When you’re through, you need to roll the bearing for the grease to get to all the inner parts of the bearing. Make sure you wipe off the excess grease from the body of the bearing.

Step 6:

Cover it with the rubber seal and wipe it again.

How Much Grease Do You Put in a Bearing?

The quantity of grease to dispense depends on the size of the ball bearings. The bigger the bearing, the more grease you’ll need to dispense. Besides, there’s no fixed quantity of grease for different bearings. You just need to dispense grease until all the balls have enough grease. 

If you decide to inject grease without removing the seal, you should stop the injection when grease begins to pop out from under the seals. Generally, bearings need about 8 grams of grease every 10,000 hours.

How Often Should I Grease a Ball Bearing?

As explained above, bearings need 8 grams of grease every 10,000 hours. So, it depends on the quantity of grease that your bearing dispenses. For instance, if your grease gun dispenses about 1.35 grams per stroke, it will take 6 strokes to achieve 8 grams.

10,000 hours amount to 60 weeks. That means 6 strokes (8 grams) of grease will last for 60 weeks. Furthermore, 1 stroke will last for 10 weeks (60 weeks divided by 6 strokes). So, you should give each bearing a stroke of grease every 10 weeks.

How to Grease a Bearing without Removing its Seal?

This is quite easy with a bearing that has rubber seals. You need to get an injection needle and fit it to the mouth of your grease gun. The needle can easily pierce through the rubber seals of any bearing. Just stick the needle into either of the rubber seals. Pump some grease into the bearing until it starts to come out from under the seal. 

Spin the bearing to distribute the grease evenly among the balls. And wipe off all excess grease from the body of the bearing.

How Long Does Bearing Grease Last?

According to experts, when subjected to heavy usage, 8 grams of grease will last for up to 10,000 hours. When you convert 10,000 hours to days, you’ll arrive at approximately 417 days or about 60 weeks. In other words, 8 grams of grease will last in a bearing for 1 year and 51 days.

What Happens If I Over-grease a Bearing?

If you over-grease any bearing, it will eject the excess grease gradually as it rolls. The problem is that the machine’s efficiency and speed will drop during the process of churning out the excess grease. This will lead to a temporary loss of energy. The issue may correct itself when the excess grease has been ejected totally. 

What Happens if Bearings Aren’t Greased?

When a bearing runs out of grease, rusts and scratches may occur in the bearings. These scratches may lead to overheating, more friction, and bearing failure. Remember that bearings are parts of bigger machinery. When the bearing fails, it could affect other components of the machine. So, it is very important to grease your bearings as and when due. 

Final Words

Greasing a bearing needs an injection needle that will be fitted to the mouth of your grease gun. And if the seals of your bearing are rubber seals, you can dispense grease with or without removing the seals. Make sure to spin the inner wheel of the bearing to distribute the grease evenly.