Posted by admin at 13 April 2015, at 15 : 40 PM
The most important trailer maintenance item has to be wheel bearings. Neglected wheel bearing maintenance will most likely leave you stranded with costly damage to your trailer! Poorly maintained wheel ends will overheat due to the lack of fresh grease and can actually catch on fire!
Listed below are step by step instructions on how to properly re-grease/re-pack your wheel bearings. Also, the instructions focus on the Hub and Drum parts only.
Don’t even attempt this type of trailer maintenance without a quality jack with enough capacity to easily lift your trailer and a minimum of 4 automotive style jack stands to safely support your trailer while it is up in the air!
Step 1: Make sure you have replacement grease seals for your particular axle hub and drum combination. Never try and re-use the old grease seals because it is impossible not to damage them as you pry them out.
Step 2: With your trailer safely supported by jack stands, remove all 4 tires. Now is a good time to check for uneven tire wear patterns.
Step 3: Pry off the grease cap to expose the castle nut which holds the whole thing together. Note, on some grease caps such as bearing buddy style caps it works better to tap the cap with a rubber hammer as you turn the hub by hand rather than using a screw driver to pry it off.
Step 4: Now straighten and pull out the cotter pin.
Step 5: Loosen and remove the castle nut and washer.
Step 6: Pull the hub towards you a bit and the outer bearing will pop right out!
Step 7: Flip the Hub over and pry out the grease seal. Usually a large screw driver or a small pry bar works well and lift the rear bearing out.
Step 8: Now it’s time to get everything all cleaned up! This is where a solvent type parts washer comes in, but if you don’t have one, a 9 x 13 metal cake pan and paint thinner works fairly well.
Clean all the bearings really well, blow them out with compressed air and set them on some clean paper towels. Set your hubs in the parts washer/cake pan and clean them out and wipe them down as well. Also use a solvent soaked towel to wipe off your axle spindles and inspect them for wear.
Inspect the bearing races inside the hub as well as the bearings for signs of wear marks, grooves, or pits. If there is any doubt about signs of bearing wear, your local auto parts store should have or can get bearings. Races on the other hand are pressed in the hub, but most auto service centers have the capability to remove and replace them. However, the races themselves will need to be purchased from a trailer parts dealer. The good news here is that races don’t usually go bad unless you haven’t stayed up on trailer maintenance outlined here!
Step 9: Now it’s time to put everything back together. Basically there are 2 ways to repack your bearings with grease. Most do-it-yourselfers do it by hand, which I will show you first. Take some grease, I usually like to use a high grade synthetic, and put a small amount in the palm of your hand. Then grasp the bearing with your index finger through the center and need the grease through the bearing rollers.
Need it long enough until it oozes out the other side. Work your way around the bearing until a small amount oozes out around the entire bearing.
Now for the easy way! They make a fairly inexpensive tool that is basically 2 funnels that clamp onto the bearing. The bottom funnel has a grease passage that injects grease through the bearing with a standard grease gun. Pretty simple tool to make your trailer maintenance easier! Bottom line here is, don’t just smear grease on the outside of the bearing!
Trailer Maintenance – it’s almost done!
Before you start, make sure you have greased every bearing and have set them in pairs on some clean towels. Also, I am assuming that you cleaned the castle nuts and washers with all the parts in previous steps. If not, do it now before you start the next step.
Step 10: Take the hub and lay it outside down on the table. Take a generous portion of grease and smear it on the rear bearing race inside the hub and lay the large bearing in it. Next, set a new grease seal over the bearing. Tap it evenly on both sides (90 degree’s apart) to start the seal into its groove.
Now rotate the steel bar 90 degree’s and continue to tap the seal in. It is seated fully when it is flush with the drum surface.
Step 11: Now everything can go back together in reverse order with only a couple of critical things to look out for.
First, smear a thin layer of grease on the entire spindle surface.
Second, slide the hub back on the spindle after smearing a generous portion of grease on the outer bearing race. Be careful not to damage the new seal as you slide the hub on.
Third, push the outer bearing in place and install the washer and then the castle nut, and tighten the nut as you turn the hub. Tighten the nut until you feel some noticeable resistance, and then back the castle nut off until the next looser cotter pin slot lines up on the spindle. Install a new cotter pin and bend it over around the castle nut making sure that no part of the cotter pin is rubbing the bearing or hub.
Fourth, tap the bearing cap back in place with a block of wood and a hammer, and you are set!
This is a preventative form of trailer maintenance that could cost you big if not performed once a year minimum!