If you are one of the thousands of people that purchase a Haul Master Trailer from Harbor Freight Tools the process of setting up and building the trailer correctly will take you a few days. You probably can complete it in about 4 hours if you just don’t care.
I am in the process of doing this myself and there is a part that needs a little more explaining than the instruction manual provides.
I will only be explaining the removal of the rear / inner bearing and seal in this how to and other how tos will explain the packing of bearings and other assembly requirements.
The process of installing the wheel hubs require repacking of the bearings in the hub. If you are not experienced at this or if you learned on your own or by taking suggestions from people online you might end up destroying some brand new parts just so you can assemble your trailer. This is not necessary and if you do it the right way you won’t be waiting weeks for a new seal or set of bearings.
It seems from reading many suggestions from other owners that the grease that comes from the factory in the wheel bearings is more of a packing grease to protect the bearings from rusting while sitting in a warehouse and it should be replaced. I am not certain that this grease is Vaseline or packing grease but it is definitely not a high speed, heavy duty, high temperature grease which is what you must put in a trailer hub.
The problem you will face when building your trailer is that the inner bearing seal is installed. This means if you use a bearing seal puller or something worse like a screw driver to get it out you will destroy it.
The Grease Seal is used to retain grease in the bearing over time. The front bearing has a hub cap and its bearing must be packed manually at an interval based on use. If you use your trailer every day then you might have to pack the bearings every month. If you use it a few times a year then you can service your bearings once a year. It depends on the mileage, speed and other factors. Servicing requires disassembly of the hub and the manual cleaning and repacking of the bearings.
The front bearing is relatively easy to get at. You remove the bearing hub cap and then remove the cotter pin and castellated nut. The entire hub will now come off with the bearings. I suggest you keep the hub mounted in the tire and wheel while working on it because it allows better control.
Removing the Inner Bearing and Seal on your Trailer
Once you have the outer bearing and hub removed but still mounted to your tire and wheel the process of removing your inner bearing and seal is not too difficult but it does require care.
Use a paper towel and clean the back of the inner bearing by stuffing it through the outer bearing and through the center of the hub.
Once it is pretty clean in there you will see the two inner rings of the roller bearing. You will also see the outer most ring which is the back of the race.
The bearing race ring is about 1/8th inch thick and you will only be hammering on this ring to remove the bearing all in one piece. See Image Outside Race. You will be tapping the back of the outer most ring you see when looking into the hub.
Some people like to use a long center punch to tap on the back side of the race ring to force it out the back. I would suggest that you use a socket wrench extension so you do not cause damage.
Place the female end of the extension into the hub and press its edge to the outside wall of the hub and down on to the bearing race. Remember we are only tapping on that outside ring that is 1/8th inch wide.
When tapping out the race you want to do it evenly so it will not get cocked in the hub and possibly get deformed.
Give a firm tap at 12 o’clock and then move to 6 o’clock and then to 3 o’clock and then to 9 o’clock.
Follow this pattern as you tap out the entire race, bearing and seal.
It should only take a firm but light tapping of a few pounds pressure but it will take many taps to get it free. Less pressure is better. Take your time you only have two of these to do.
Once the race is forced far enough through the hub the seal will pop out and the bearing will drop off so you should put a shop towel or crumpled paper towels under it to catch the bearing and seal.
You do not need to remove the inner bearing race completely if you are only removing the bearing seal and roller bearings for repacking. Just tap it out far enough so the seal pops off.
Using a matching sized but slightly smaller socket you can then reinsert the bearing race by tapping it back into place. The best method would be to use a bearing race installer but if you don’t have one and can’t run out to buy one a socket or even a center punch will work.
Remember to seat the bearing race evenly. Inspect that it is seated by placing your finger into the hub and feeling for a gap. If you can not then use a visual inspection.
At this point your parts are ready for servicing and you have not destroyed your bearing or bearing seals.
You will need to clean all the parts and then repack the bearing with high temperature heavy duty wheel bearing grease.
Use a proper degreaser such as brake cleaner and not a general purpose solvent that could end up breaking down your new grease. If you have compressed air blow the bearing dry before packing.
Remember clean all parts to remove metal fragments that can destroy your bearings very quickly.
Set aside a good hour and a half to complete this job including repacking the bearings and installing them on the axle.
You will need brake cleaner, High Temperature Heavy Duty Wheel Bearing Grease, Hand Tools and a bit of luck to not slip and trash your bearings.