Repacking Bearings – Why & How (Part 1)

Why repacking bearings is important

Over time, grease breaks down, heat that is produced by the brakes speeds this up, and since a trailers weight rides on the wheel bearings it is very important to keep them well lubricated. This can be a quick DIY job if you know what you are doing, if you are unsure, call your local mechanic to make an appointment.

You may have heard the term “repacking” bearings, and owning a trailer it is a good idea to know how to clean and “repack” them.  Repacking a bearing is the process of removing the parts of the wheel to access, clean and add grease to the bearings.

Over time the bearings will take a large amount of abuse and wear, although they are designed to last for a long time, they will wear out prematurely if they are not routinely taken care of. They will eventually wear out, but you can extend the span of them by maintaining them.

How to Know if The Bearings are Damaged

When wheel bearings are packed with grease correctly, it spins freely and does not develop excess heat. If the wheel bearing fails, it is often due to a lack of grease inside the wheel bearing housing.

If the wheel bearing is damaged, it can cause the tire and wheel to not align to the hub, this creates abnormal tire wear. It can lead to excessive wear on the inside or outside edges of the tires. Mechanical problems can arise as well including damaged shocks, struts, suspension out of alignment and over or under inflated tires.

Bearings will often create unnatural sounds that, depending on speed, will often indicate that the bearings need attention.

Some good tips to follow are:

  • Do NOT reuse cotter pins, they are one of the least expensive parts and is one of the most important.
  • Make sure to thoroughly clean all old grease from the bearings, races and hub cavities using brake cleaner. There are some greases out there that are not compatible with others.
  • The general thought consensus is that trailer wheel bearings should be serviced annually or every 10,000 km. Grease can break down on stored trailers, then corrosion can form.
  • Looking closely at the bearing and race surfaces to see if there are any nicks or discolorations. If there are you will want to replace all inner and outer bearings and races on both sides.

Mistakes That are Common

There are 3 main mistakes made when repacking bearings that some inexperienced trailer owners make when completing the routine maintenance of their trailers. These mistakes can result in more frequent repairs and higher costs.

1. Using the wrong grease:

Using the wrong grease could be as bad as using no grease. The wrong grease will leave the bearings exposed to metal on metal contact as you tow your trailer. Select a grease that is rated for what you will need on the trailer you have, to check this you can start by checking the recommendations in the trailer manual.

2. Lubricating is based on time, instead of condition:

Bearings need grease for one reason only, to reduce friction. There should be no reason to change it as long as the lubricant is performing well. You do not need to lubricate just because the calendar said it is time. Check the bearings and gauge if repacking is needed.

3. Over or under lubrication:

Too much grease can build pressure, this causes the bearing to have to work much harder to push the rolling elements through the bog of grease. The increases friction raises the temperature inside the bearing, that could decrease the effectiveness of the lubricant causing the oil to separate.

Watch for our “How to Repack Your Bearings” blog coming in a couple of weeks.

Reference Links:

https://www.familyhandyman.com/project/repacking-trailer-wheel-bearings/

http://blog.championtrailers.com/repacking-bearing-mean

https://www.maintworld.com/Applications/The-Three-Mistakes-of-Bearing-Lubrication

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