Here, at the Trailer Parts Superstore, we often get calls from frustrated customers who have found out that their trailer has been outfitted with a suspension salvaged from a mobile home transport.  A little history: when mobile homes were first being introduced, some of the builders asked the Dexter Axle Co. to develop a low cost suspension system for limited use only for the transport of the mobile homes of the day.  Dexter developed a suspension that was accepted and was in wide use during the heyday of the mobile home.  This system was not approved by DOT, but approved by HUD (Housing and Urban Development).  It was called the MHA (Mobile Home Axle) and was supposed to be disposable.  Unfortunately, opportunists would salvage these suspensions and re-use them on old trailers and even new trailers.

This suspension consisted of an axle with drum brakes and springs. Even though the axle could be rated at 6000lb, the spindle, bearings and hub de-rated it to 4500 lb.  The brake assembly backing plates were welded to the spindle and they could be rebuilt but not replaced.  Brake rebuild parts can still be ordered directly from Dexter. The springs were a low quality mono-leaf and can be replaced with a 25.25” double eye leaf spring.

25-1/4″ Double Eye Trailer Leaf Spring (4 leaves) #US-1067

The inner bearings are 68148
Timken® 1-3/8″ Bearing Cup & Cone Set #17

and the outer bearings are 67048
Timken® 1-1/4″ Bearing Cup & Cone Set #6

The wheel that is used is called the “Demountable” rim.
Demountable Trailer Wheel Rim and Tire

with a tire like this:
LOADSTAR 8-14.5″ LT Heavy Duty Tire, Load Range G

and matches with the Demountable Brake Drum
DEXTER 12″x2″ 5-Spoke Wheel-Drum Kit: Demountable 6k UTG Axles

that mounts with
DEXTER Rim Clamp for Demountable Drum

Dexter Axle also developed a more flexible system called the MHU (mobile home utility) that allowed users to change to standard drums and wheels and used replaceable Brake assemblies. This system was rated at 6k, had larger bearings more expensive and not as prevalent in the market place as the MHA.

Trailer Brake Fluid tips from Tie Down Engineering

Trailer Brake FluidTie Down Engineering recommends changing brake fluid every two years for marine trailers and every three years for utility trailers.

Brake fluid is one of the most neglected fluid in vehicles today, yet is vitally important for safe towing. Consequently, trailer owners should check the fluid in both the tow vehicle and the trailer on a regular basis. The brake fluid should be changed if it is contaminated. The issue is that old brake fluid may not be safe if moisture contamination is above a certain level.

Many experts have long recommended changing the brake fluid every year or two for preventative maintenance. Their rationale is based on the fact that glycol-based brake fluid (DOT 3 & 4) starts to absorb moisture from the moment it is put in the system. The fluid attracts moisture through microscopic pores in seals and exposure to the air. The problem is obviously worse in wet climates where humidity is high and with marine trailers constantly subjected to dunking in lakes, rivers or oceans.

DOT 5 cannot be used in trailer brake systems unless specifically stated by the actuator and brake manufacturer. DOT 5 does not absorb water, however the silicone in the DOT 5 makes the seals swell and can bind up caliper pistons.

Silicone has several other properties that make it less then desirable for trailer use. When forced thru small orifices under high pressure, like the solenoid valves in a disc brake system, it tends to foam, generating bubbles. Bubbles in brake fluid make for spongy brakes. Silicone also tends to become slightly compressible at temperatures near its boiling point, which makes it generally inappropriate for trailers used in mountain conditions. Tie Down Engineering brakes are designed for DOT3 or DOT 4 fluid ONLY.  NEVER USE DOT 5.

Water can actually cause air to accumulate in your brake lines. Brake fluid is hygroscopic. It absorbs and retains water. The problem arises when the fluid has absorbed as much water as it possibly can and becomes saturated. Brake fluid is designed to have an extremely high boiling point; however, if you subject your tow vehicle and trailer to excessive braking, such as a trip through the mountains, you can easily cause the brake fluid to heat up to this temperature or beyond. When the brake fluid boils, especially when there is excessive water in the system, steam is a by-product. The braking system ultimately compresses this steam and turns it into water. The air separates from the water creating large pockets of air in your brake lines.

After only a year of service, the brake fluid in the average marine trailer may contain as much as two percent water. After 18 months, the level of contamination can be as high as three percent. And after several years of service, it is not unusual to find brake fluid that contains as much as seven to eight percent water.

As the concentration of moisture increases, it causes a sharp drop in the fluid’s boiling temperature. Brand new DOT 3 brake fluid must have a dry (no moisture) boiling point of at least 401 degrees F, and a wet (moisture-saturated) boiling point of no less than 284 degrees. Most new DOT 3 fluids exceed these requirements and have a dry boiling point that ranges from 460 degrees up to over 500 degrees.

Only one percent water in the fluid can lower the boiling point of a typical DOT 3 fluid to 369 degrees. Two percent water can push the boiling point down to around 320 degrees, and three percent will take it all the way down to 293 degrees, which is getting dangerously close to the minimum DOT and OEM requirements.

So consider this: After three years of service, the average boiling point of the brake fluid has dropped to a potentially dangerous level because of moisture contamination and may not meet minimum federal requirements for brake fluid.

Water Contamination increases the danger of brake failure because vapor pockets can form if the fluid gets too hot. Vapor displaces fluid and is compressible, so when the brakes are applied the actuator may completely compress without applying the brakes!

In addition to the safety issue, water-laden brake fluid promotes corrosion and pitting in caliper pistons and bores, wheel cylinders, master cylinders, steel brake lines and reverse solenoids.

From time to time we hear about reports of “unexplained” brake failures. When the vehicle’s brakes are inspected, no apparent mechanical fault can be found. The fluid level is normal, the linings are within specifications, the hydraulics appear to be working normally. Yet the brakes failed. Why? Because something made the brakes hot, which in turn overheated the fluid causing it to boil. The underlying cause often turns out to be dragging brakes caused by the E-stop cable being tripped, or the use of DOT 5 Fluid, but that is another story.

Do A Corrosion Check On Your Boat Trailer

Galvanized U-Bolts

Galvanized U-Bolts

If you have been towing a boat trailer for any length of time, then you probably have at least one roadside horror story to tell. Keeping a boat trailer safely on the road is not an easy task. Of course, salt water accelerates the corrosion process. Once a trailer is more that a couple of years old, it is wise to start inspecting the many trailer components at least once per year.

Most boat trailers are bolted together. You should always start by inspecting all bolts, nuts and washers, especially those that get immersed during launch and retrieve. The most important hardware to check is the u-bolts that fasten the leaf springs and axle together. These u-bolts actually are the only thing holding the axle to the rest of the trailer. A little surface rust is not a problem but corrosion will actually degrade the u-bolts to the point that they can no longer handle the stress imposed at this point. Other suspect hardware is as follows:

* Axle to spring tie plate u-bolts
* Leaf spring center pins
* Spring shackle bolts
* Spring hangers and equalizers
* Fender hardware
* Bunk/roller bracket to frame hardware
* Lug nuts/bolts, studs
* Cross-member to frame hardware

In addition, the frame, axles and cross-members should be inspected where it has contacted corroded hardware. We have seen a few incidents where the cross-member or axle integrity has been compromised at this point, especially on trailers with aluminum frames.

The solution to these corrosion problems is to replace the compromised hardware with new stainless or galvanized such as this:

1/2″ Galv. Square U-Bolt, 2-1/16″ x 4-13/16″ #86223

If you cannot find galvanized or stainless hardware, a good compromise is to use zinc-plated products with a good coat of a product such as this:

Instant Galvanize Spray Coating, 13 oz. #06054

There are already enough hazards on the road when towing a boat. Don’t wait for corrosion to reduce your safety footprint. Try some of these tips and tow your boat with a more secure feeling. You can find these products along with many replacement trailer parts at our online store TRAILER PARTS SUPERSTORE

Dexter Nev-R-Adjust Electric Trailer Brakes

Nev-R-Adjust Trailer brakes

Nev-R-Adjust Trailer brakes

Electric drum brakes (10” and 12”) are the norm for most trailers rated less than 15000 lbs. These brakes have always been considered cantankerous because of the problems caused by brake lining wear. This normal wear requires periodic adjustment of the brakes that may or may not be performed. If not performed, the trailer could lose as much as 50% of the potential braking power. With the lost trailer stopping power, the tow vehicle has to over-work its brakes.

So says Dexter Axle as they have developed a solution to this problem in their new line-up of trademarked Nev-R-Adjust electric drum brake assemblies. They have used technology already available in heavy-duty truck and trailer brakes and adapted it to the smaller 10 inch and 12 inch electric brakes found on most RVs, utility, horse trailers etc.

Dexter accomplished this self-adjusting feature by adding a 9 piece “Adjuster Kit” to the standard brake assembly backing plate. This allows the brake assembly to constantly adjust the lining position as the brake drum turns during trailer operation. In speaking to Dexter’s Engineering team, the adjustment feature works as the trailer moves in both forward and reverse directions but the increments of adjustment are much higher in reverse. Since there are specific brake assemblies designed for the driver-side and curbside of the trailer, problems will occur if the brake assemblies were installed on the wrong side of the trailer. Brake assemblies mounted on the wrong side will act like they are traveling in reverse. This would cause “over-adjustment” and can cause the brakes to overheat and lock. Therefore, for self-adjusting brakes, it is imperative that the proper brake assemblies are installed on their specified side of the trailer.

Dexter introduced their 12 inch self-adjusting brake assemblies in May of 2008 and their 10 inch unit in May 2009. They performed extensive reliability testing using a dynamometer and also real life testing on their own trailer fleet before they marketed the product. They offer a 2 year limited warranty on these products.

It seems that recreational trailer owners have been the first to embrace this new product offering with more commercial trailer owners loyal to the standard product. The new self-adjusting brake assemblies cost about 20% more than standard brakes.

Trailer Parts Superstore offeres both sizes online at: ELECTRIC TRAILER BRAKES


Trailer Axle Camber

Trailer Axle Camber

There are several different parameters that are very important to finding a new axle for a trailer. The most obvious is the Gross Axle Weight Rating that defines the load properties of the axle (and trailer). Typical values of GAWR are 2200 lb, 3500 lb 5200 lb etc.

Other values that are important in defining a trailer axle are Track Length (center of tire to center of tire), Overall Length and Spring Center (center of spring to center of spring).

Camber is another property that is defined by the trailer axle. Actually, camber is the effect of the tire alignment on the pavement as illustrated above.

Most trailer axles are designed with a “bend” in the tube that will deflect when the load (weight of the trailer) is applied. This will theoretically bring the trailer wheel camber toward a 0 value that is the best setting for most trailer applications. This will allow the tires to wear evenly and allow the longest tread life. Camber can be affected by damage to the axle. For example, if the axle spindle is bent, this will usually cause a negative camber on that side which will cause excess tread wear on the inside of that tire.

Both Sprung axles and Torsion axles typically are built with a slight positive camber but custom axles can be specified with or without camber. A trailer that runs long distances without a load may be better without axle camber. An example of this might be a long distance boat transport trailer.

Axles and related products can be seen online at:


Tractor Trailer Parts

Tractor Trailer Parts

After a few years on the road and enduring all kinds of weather, even a brand new commercial trailer can look much older than it should. Trailer Parts Superstore offers dozens of replacement items and upgrade accessories that can improve the appearance and functionality of your Semi Tractor Trailer.


First, changing the Coiled Air hose assemblies over to Phillips POLAR AIR brand allows this product to stay flexible to –85 degrees and will give a new look to the area behind the cab.

Two other accessory items that would also improve the appearance of this area are the 40 in Chrome Pogo Stick and the Stainless Steel Tracker Bar kit.

Our 100 mil polished diamond tread aluminum underbody toolboxes from Buyers Products will look great and we have several sizes to fit in just about any space.

New LED taillights and marker lights are the best way to add some flash to your semi-trailer. They are also brighter than the old incandescent bulbs and will an added safety feature. Trailer Parts Superstore has a large selection of standard and LED lights.

Lastly, new mud flaps always make your rig look new.

You can see these products and many others at:
Trailer Parts Superstore


Boat Trailer Parts

Boat Trailers are different from other types of trailers and RVs because they get immersed in water (often salt water) and that accelerates corrosion or rust. A definition of corrosion is “development of metal oxides on the surface of a metal part”. With steel as the metal, iron oxides are the compounds that form rust (Fe2O3/FeOOH). Rust starts on the surface but if not corrected, will corrode the part until it fails. If this happens, the part will need to be replaced. Finding parts for specific brands of boat trailer is not easy because many manufacturers have closed their operations years ago.

The traditional method to help retard corrosion in boat trailer components is to galvanize using hot dip zinc. Zinc electro-plating will help but due to the plating porosity, corrosion will gradually erode the part. Aluminum is also frequently used as a material.

Eastern Marine specializes in replacement parts for boat trailers. Just about any part you need is available including axles, leaf springs, brakes, winch post parts, etc. If you have a Load Rite trailer; then select LOADRITE Factory Trailer Parts. If you have an EZ Loader trailer, select EZ-LOADER Factory Trailer Parts .

It a few weeks we will be offering a new product line that will be of interest to owners of older boat trailers… the galvanized square tube universal axle. These 2” x 2” axles will be supplied by Tie Down Engineering and be available in 2000 lb rating (up to 96 inch overall length) with a 1-1/16” straight spindle. The 3500 lb axles will also be available up to 96” overall length with a standard 1-3/8” x 1-1/16” spindle with brake flange. What makes them universal is that the customer will have to drill holes in the tube for the spring seat position exactly as it is on the axle being replaced. This position varies for each trailer manufacturer. We would recommend treating the drilled area with a corrosion preventive product.

This new product will be just the ticket for owners of discontinued trailer brands like Calkins, Cox, Shoreline, Holsclaw, Escort, Long, Dilly, Performance etc. and can be seen at TRAILER PARTS SUPERSTORE


Fulton Trailer Lock

Unfortunately, we have many customers relate stories of their trailer being stolen. Often, the trailer is loaded with valuable tools or favorite toys like boats or snowmobiles etc. One particularly disturbing incident involved a trailer owned by a Boy Scout troop where they lost all their equipment. There are many options available to trailer owners to reduce their risk of theft. I want to review some of these in this article.

There are several strategies available to trailer owners to reduce their risk of theft, some as simple as a lock. All have some merit. The first position on the trailer that can be locked out is the coupler on the a-frame or trailer tongue. There are several versions of this type of lock available, but Fulton’s Universal Fit Coupler lock is very functional and cost-effective. Simply put, it is a heavy cast metal base with a ball to fill the coupler with a stainless bar over the lever lock to prevent access.
FULTON Universal Fit Trailer Coupler Lock #ULT1000600

If you want to reduce your risk when the trailer is coupled to the tow vehicle, try this:
DEADBOLT Class-3 & 4 Receiver Hitch Lock #RH3

If interested in keeping your wheels from turning to prevent theft, this would be helpful!
Lock’em Magnum Wheel Lock #RA25

And for a complete trailer security system, this is available with many accessories.
TRAILER DOG™ Security Alarm Systems

As you can see, there are several different strategies that can reduce your risk of having a valuable trailer stolen from your property and all can be viewed online at:


CALIBER Snowmobile Trailer Accessories

Caliber Trailer Products makes molded components that help protect the decks of Snowmobile and ATV trailers and are designed specifically to aide in loading, unloading and securing these vehicles on their trailers. The company has developed an easy-to-use online program so that customers can design the track – glide systems on their Snowmobile or ATV trailer decks. This program is called the “Trailer Configurator” and allows customers to select the appropriate Caliber products in the correct amounts without any professional help. This tool is available online at the following link:  CALIBER PRODUCTS

Trailer Configuration:
1. Select your Snowmobile/ATV trailer type (Open Trailer, Open V Front or Enclosed)
2. Enter trailer length
3. Select the GLIDES function
4. Select TRACTION function
5. Select ADDITIONAL OPTIONS function

This is the most efficient way to rig your trailer for the coming season. Check it out!

CALIBER Snowmobile Trailer Parts Offering Expanded

CALIBER Snowmobile Trailer Accessories

Trailer Parts Superstore has recently added to our offering of CALIBER™ brand Snow Mobile/ATV Trailer Accessories. These items are designed specifically to aide in loading, unloading and securing snowmobiles and ATV’s. Many of these specialty components are designed for specific trailer types including: straight front open trailers, V-front open trailers, V-Door enclosed trailers and all types of trailer ramp gates.

Check out our complete offering here: