Keeping the bottom side of a trailer properly maintained will lead to good times down the road
Trailer maintenance and good times go hand in hand. This statement may sound odd from the outset, but it’s true. Properly maintaining your trailer means that your family vacations won’t be rudely interrupted by mechanical failures. And, if you’re the type who likes to tinker, maintenance can actually be cathartic — just you, your trailer, some tools and dirt. If you’re working on the undercarriage, make that lots of dirt.
Axle bearing and brake maintenance are two of the most important aspects of trailer ownership, but it’s surprising how few RVers pay attention to these humble assemblies. Perhaps it’s an out-of-sight, out-of-mind thing, but axle bearings and brakes are two of the most important components on any trailer — we’re sure you’d agree that being able to carry a load and stop safely are pretty important. And the good news is, maintenance really isn’t that difficult, once you know the process. All you need is a floor jack, jack stands, some basic hand tools and axle grease, and you can save yourself a lot of time, money and trouble.
While you’re down there, you might consider upgrading the factory leaf-spring suspension. The factory suspension uses plastic bushings that wear out quickly, causing alignment problems that can lead to uneven tire wear. Dexter Axle Company offers heavy-duty suspension kits that let you replace the spring equalizer with a greasable unit, discard the stock shackle plates in favor of beefier ones and upgrade the bushings with bronze replacements. The kits are very reasonably priced and aren’t difficult to install.
To see what’s involved, we visited C&S RV Service Center in Oxnard, California, where the team was getting ready for work on a ‘90s-vintage toy hauler. The new owner wanted to make sure the trailer was ready to hit the road for the summer travel season, which was a wise decision. This job took only a few hours and, remember, you don’t have to do it all at once — this could be a nice weekend project.
Now let’s follow the guys at C&S and see how it’s done.
(1) Use a floor jack under the frame to lift the trailer high enough to remove the wheels; make sure jack stands are used to support the frame. You can now remove the dust cover that protects the axle bearing. If you don’t have this special tool, a pair of Channellock pliers can be used to carefully remove the cover.
(2) Straighten and remove the cotter pin, then use a pair of Channellocks or a socket to remove the nut. It should not be very tight.
(3) Give the brake drum a sharp, short tug, and the outer bearing will pop out. Be careful not to let the bearing hit the ground. If in doubt, lay a folded towel underneath to protect the bearing if it falls.(4) Pull the drum, and the spindle and brake mechanism will be exposed.
(5) Technicians use a specialized tool to remove the seal from inside the brake drum, but this could be pried free with a large flat-blade screwdriver.
(6)With the old seal out of the way, the inner bearing can be removed.
(7) Wipe the bearings clean with a rag and inspect the rollers for pitting or other types of damage. The inner race of this bearing is just starting to show the bronze layer underneath, indicating wear, but not enough to require a new bearing this time around.
(8) Don’t be concerned if the spindle appears to have damage like this one (arrow A). This was the way the spindle here was cast and machined, and although it’s not pretty, it doesn’t hurt anything. What you are concerned with is damage to the bearing surfaces (arrows B and C).
(9)A quick inspection of the drum revealed that this brake had not been functioning for a while, as evidenced by rust on the contact surface.
If the brake were working properly, this surface would be polished metal. This could mean that the magnets are no longer working or simply that this brake needs adjustment. To check the magnet, make sure the battery is connected and have a friend pull on the breakaway-cable plug. If the magnet strongly attracts metal, it’s working.
(10)Clean the grease away from the inside of the drum and inspect the inner race. Usually, if the bearing appears to be in good condition, the race will be, too — but it doesn’t hurt to double check. This race seems to be in good condition with no pitting or scoring. Now is also a good time to inspect the magnet contact surface for scoring. Scratches like these are normal — what you’re looking for are deeper grooves that may require that the drum be resurfaced.
(11, 12) Thoroughly clean the brake drum and mechanism with brake cleaner before reassembly.
(13) If you don’t know how to pack the bearings by hand, and you plan on doing more work like this in the future, you may want to invest in a bearing-packing tool like this one (they’re available for about $20). The reservoir is filled with bearing grease, and the bearing is placed on top. When the plunger is depressed, grease is pushed into the bearing. When it oozes out of the top between the bearing rollers, the bearing is properly packed.
(14)Repack the inner race with bearing grease. This looks like a lot right now, but the excess will be wiped away. Reinstall a new seal, then carefully tap it in place so it seats evenly. C&S uses a flat metal plate for this purpose.
(15) Reinstall the drum and apply a liberal amount of grease to the spindle, then complete the assembly. Tightening the nut correctlyis a delicate process that requires a light touch. Typically, the process involves tightening the nut while spinning the drum until resistanceis felt. Then, back off the nut and retighten finger-tight. Either tighten or loosen the nut to install the cotter pin, according to the manufacturer’s instructions.(16) Now the brake can be adjusted. Use a brake spoon in the slot on the back side of the assembly to rotate the adjuster. Rotating it down tightens the brakes; rotating it up loosens them. Adjust the brakes until there is some drag, but the drum can still be turned by hand.
(17)The leaf-spring eye and equalizer bushings are plastic and wear out very quickly. To upgrade to the Dexter Heavy Duty Suspension, the first step is to spray the hardware with WD-40, then remove the nuts.
(18) Use a sledgehammer to remove the old bolts — you will not be reusing them.
(19) The new bronze bushings are driven in place — and the old ones driven out — using a new bolt as a dowel.(20) This is why replacing the stock plastic bushings is important. They wear out in only a few thousand miles, creating slack and misalignment in the suspension.
(21)The new Dexter equalizer is not only more substantial than the factory piece, it has bronze bushings preinstalled and a grease fitting to keep the bushings properly lubricated.
(22, 23) The new equalizer and spring eye bushings have been installed, and now it’s time to reassemble the suspension with the heavy-duty shackle plates. As you can see, they’re much more robust than the factory pieces.
(24) The finished suspension looks good and is ready for many more trouble-free miles. q