Dexter FAQ's, Dexter Axle Frequently Asked Questions

Dexter FAQ's

	AXLES - Can I buy axles directly from Dexter? All Dexter axles are manufactured specifically for each customer order. Since there are literally tens of thousands of size and option combinations, we do not stock any axles. Therefore, every order must be set-up to produce. While we do sell axles direct, it is generally less expensive to purchase small quantities of axles through our distribution network. Because they buy in volume, they can supply axles at a more reasonable price than factory-direct due to set-up and freight costs. There is a complete list of Dexter Axle authorized distributors on our web site. Those coded with "AB" stock bare axle beams and can provide complete axle assemblies with a very short lead-time.
	AXLES - Can I buy just a spindle? It is against our policy to sell loose spindles for axles. The installation, alignment, and welding of the spindles is the most critical operation in the manufacturing of axles. It requires sophisticated alignment fixtures and precision welding to insure the proper attachment. The only recourse is to obtain a new axle beam. On a sprung type axle, this is the tube, spindle, and spring seat. On a Torflex axle, this is the tube, inner bar, rubber suspension, spindle, and bracket assembly.
	AXLES - Can axles be used without suspensions? Axle capacity will be reduced by at least 50% when used without a suspension system (axles or stubs attached directly to the vehicle frame). This is NOT a recommended configuration as it transfers load directly to the frame rails and is a very harsh ride.
	AXLES - Can mobile home axles be reused? The Dexter MH (mobile home) type axle is designed for limited usage in the delivery of manufactured homes and has a one-time limit use. The axle has steel forged spindles that are not precision ground. The brake assembly is welded onto the beam and not intended to be field replaced. Additionally, the bearing package is smaller than the more expensive service type axle. Most MH axles are also equipped with a single leaf spring suspension for very heavy loads. We do not have components that would convert MH axles to serviceable assemblies.
	AXLES - What type of warranty does Dexter Axle offer? Dexter Axle warrants to the original purchaser of a recreational vehicle manufactured by RVIA (Recreational Vehicle Manufacturer's Association) members for private non-commercial use or service, that the spring suspension axles will be free of defects in material and workmanship for a period of the earlier of two (2) years from the date of purchase by the original purchaser or 24,000 miles. The warranty period on the Nev-R-Lube bearing package is for a period of five (5) years or 100,000 miles from the date of purchase by the original purchaser.
	AXLES - Where can I find replacement parts for mobile home axles? Many Dexter distributors do not stock components for mobile home style axles because the axles are intended for limited use in the delivery of manufactured homes. However, this distributor should have the item(s) you need.
	AXLES - Why are some axles bent in the middle? The upward bend in the axle is called "camber". Camber is the angular relationship of the wheel to the road surface in the vertical plane. Axles are typically built with a pre-determined bend in the tube that compensates for the expected deflection under load.
	BEARINGS - How often should I grease the bearings? Along with bearing adjustment, proper lubrication is essential to the current function and reliability of your trailer axle. Bearings should be lubricated every 12 months or 12,000 miles.
	BEARINGS - What is the proper bearing adjustment procedure and recommended grease? Please review the Dexter Service Manual for instructions and specifications relating to bearing adjustment and lubrication. WARNING: It is important NOT to mix different types of grease thickeners. The grease that Dexter Axle uses has a Lithium Complex thickener. Mixing our grease with a Barium, Calcium, Clay, or Polyurea soap based thickener agent will cause adverse affects. This may include causing the two greases to harden, separate, become acidic, or pose other hazards and damage to the bearings.
	BRAKES - Can I change my brakes from electric to hydraulic or vice versa? This can be done on most axle models. We recommend contacting the trailer manufacturer prior to changing your braking system to identify any potential problems.
	BRAKES - Can I upgrade to bigger brakes? No, the different brake sizes offered by Dexter are not interchangeable on existing axles. There are only a few cases where you may be able to upgrade with stronger magnets and more aggressive linings. Typically the problem that causes weak brakes is under adjustment in the smaller brakes that require frequent manual adjusting (see: How often should I adjust my brakes?) or insufficient brake voltage in the electric brakes (see: Why aren't my electric brakes working properly).
	BRAKES - Can brakes be added to an idler axle? Adding brakes to an idler axle is relatively easy if the idler axle is equipped with the brake mounting flanges (the plate to which the brake is bolted). About half of the trailer manufacturers decide not to put the flanges on their idler axles to reduce their cost. If the axle does have flanges, you need both a RH and a LH brake assembly as well as two hub and drums to replace the plain hubs currently on the axle. If the axle is not equipped with flanges, you will need to purchase a new axle beam with brake flanges attached by Dexter Axle.
	BRAKES - Can brakes be used on trailers towed by motorcycles? Dexter Axle does not recommend the use of brakes on small touring trailers designed to be pulled by motorcycles. Proper control of the brakes on these vehicles can be very difficult. Even the slightest imbalance of the trailer brakes might cause the rider to lose control. A secondary issue is the spontaneous and unexpected actuation of the brakes. This can occur when a Torflex axle is not fully loaded. Under this condition, the torsion arm is not rotated to its normal position, which puts the brake assembly out of level. If the axle is fitted with electric brakes, this non-level condition can result in unexpected brake actuation when the trailer encounters large bumps. This can occur because the magnet inside the brake has sufficient mass to move the actuating lever during extreme jounce situations. The farther the brake assembly is rotated out of level, the greater the chance that this spontaneous action can take place.
	BRAKES - Do Dexter brake magnet wires have polarity? The wires on a Dexter magnet do not have polarity. It works like a common resistor. One wire will connect to power and the other to a ground. It is Dexter's recommendation that a common ground be run from the trailer plug to the brake magnets. Do not ground each brake individually to the trailer frame or structure. Also note that the brakes should be wired in parallel, not in series.
	BRAKES - How can I increase the aggressiveness of the 12"x2" brake? It is not possible to put a larger magnet in the 12"x2" electric brake, nor does Dexter offer a self-adjusting brake in that size. However, we do offer a more aggressive lining. The lining kit number is K71-127-00. You will need one for each brake.
	BRAKES - How do I measure brake current or amperage? Dexter 7" brakes draw about 2.5 amps per brake and all other brake magnets draw about 3 amps per brake. The total system amperage is calculated by multiplying this number by the number of brakes/magnets connected to the brake system. To measure the brake current, the engine of the towing vehicle should be running. Disconnect the wire at the point that you wish to measure the current draw and put the ammeter in series with this line. Make sure your ammeter has sufficient capacity and note polarity to prevent damaging your ammeter. NOTE: If a resistor is used in the brake system, it must be set to zero or bypassed completely to obtain the maximum amperage reading. The amount of current draw will depend on what point you are measuring. If the ammeter is at the plug, you will get the total current draw from all magnets. If the ammeter is connected at one of the magnets, you will measure the current draw through that magnet only.
	BRAKES - How do I measure brake voltage? System voltage is measured at the magnets by connecting a voltmeter to the two magnet lead wires at any brake. This may be accomplished by using a pin probe inserted through the insulation of the wires dropping down from the chassis or by cutting the wires. The engine of the towing vehicle should be running when checking the voltage so that a low battery will not affect the readings. Voltage in the system should begin at 0 volts and as the controller bar is slowly actuated, should gradually increase to about 12 volts. This is referred to as modulation. No modulation means that when the controller begins to apply voltage to the brakes it applies an immediate high voltage, which causes the brakes to apply instantaneous maximum power. The threshold voltage of a controller is the voltage applied to the brakes when the controller first turns on. The lower the threshold voltage the smoother the brakes will operate. Too high of a threshold voltage (in excess of 2 volts as quite often found in heavy duty controllers) can cause grabby, harsh brakes.
	BRAKES - How often should I adjust my brakes? Dexter recommends that manual adjust brakes be adjusted . . . 1) After the first 200 miles of operation when the brake shoes and drums have "seated". 2) At 3,000 mile intervals. 3) Or as use or performance requires.
	BRAKES - Why are my boat trailer brakes rusting so fast? Dexter offers marine application free-backing hydraulic brakes in both 10"x2-1/4" and 12"x2" sizes. The brake components are all either E-Coated, stainless steel, or zinc plated to resist corrosion.
	BRAKES - My brake linings are cracked, do I have to replace them? Usually, light cracking of the surface of a brake lining can be expected under normal use. This is not cause for replacement. However, if the lining is deeply cracked to the shoe surface or is missing chunks, your brake linings will require replacement.
	BRAKES - Which magnet wire is the positive, they are both the same color? The Dexter magnet is not a polarized component. Use one wire to connect to power from the brake controller and use the other to attach to the ground. It is Dexter's recommendation that a common ground be run from the trailer plug to the magnets. Do not ground each brake individually to the trailer frame or structure. Also note that the brakes should be wired in parallel, not in series. The wire color is used to identify the component since so many Dexter magnets physically look the same on the outside; however they are different strengths for the different capacity brakes.
	BRAKES - Which way do electric brakes mount to the axle? The actuation lever should curve around the front side of the spindle. The wires should always exit the brake to the backside of the assembly when installed on the trailer.
	BRAKES - Why aren't my electric brakes working? Most electric brake malfunctions that cannot be corrected by either brake adjustment or synchronization adjustments of your brake controller can generally be traced to electrical system failure. Mechanical causes are ordinarily obvious (i.e. bent/broken parts, worn out linings or magnets, seized lever arms or shoes, scored drums, etc.). A voltmeter and ammeter will be essential tools for proper troubleshooting of electric brakes. NOTE: After replacing your brake shoes and magnets you will experience a decrease in braking performance until the components have worn into the drum and finished the burnishing process. This process requires many stops to bring the new shoe's performance back to normal. This may take more than 100 stops to finish this break-in period with stops of 20 mph decreases in speed. Please refer to the Dexter Service Manual for detailed troubleshooting instructions to further determine the cause of poor brake performance.
	BRAKES - Why can't I lock and slide my electric brakes? On an unloaded trailer, you may be able to lock up your brakes if your electric brake controller is supplying full amperage to the brakes. When loaded to capacity, you may not be able to lock your brakes as electric brakes are designed to slow the trailer at a controlled rate, and not designed to lock up the wheels on a fully loaded trailer. Our brakes are designed to meet all applicable safety standards. All of our brakes will perform better after numerous burnish stops to seat the brake linings to the drums.
	BRAKES - Why do I have to adjust my brakes? Brakes must be adjusted to compensate for the lining and drum wear that occurs during the use of the braking system. Some brakes require manual adjustment to move the linings closer to the drum. Refer to the brake adjustment section of the OPERATION MAINTENANCE SERVICE MANUAL for your style of brakes. Other brakes may have an automatic brake adjuster such as the automatic slack adjusters for air brakes.
	BRAKES - Why do my brakes and hubs get so hot? Braking systems use friction to slow the vehicle and the energy used to slow the trailer is converted to heat. Dexter brakes are designed to operate up to extremely high temperatures during hard braking application. This heat is noticeable on the hub and drums and is to be normally expected on a properly functioning brake. If a brake is malfunctioning and running excessively hot, this can be noticed by smoking brakes or the paint burning off of the brake drum.
	E-Z LUBE - Can I upgrade to the E-Z Lube option on my existing axles? No, the E-Z Lube option requires a specially controlled machining operation to drill the holes in the spindles to provide the grease path from the end of the spindle to the inner bearing.
	E-Z LUBE - What is the E-Z Lube option? The E-Z Lube option was designed specifically for the marine application where the axles are constantly being immersed in water. This feature provides a convenient method for purging the water from the hub cavity without having to pull the hub every time. The hubs should be removed every 12 months or 12,000 miles to inspect the bearings and it is imperative to replace the seal at this time to assure that the grease does not leak out the back onto the brake linings rendering the brakes non-functional.
	MISCELLANEOUS - How can I change the height of my trailer? Dexter offers an over/under conversion kit for leaf spring axles. The two different kits available are K71-384-00 for axles with 2-3/8" diameter tube and K71-385-00 for axles with 3" diameter tube. Please note that these conversion kits CANNOT be used with reinforced spring seats. Additionally, changing the spring mounting from underslung to overslung (or vice versa) will change the trailer frame height and change the center of gravity of the trailer. This may affect the towing characteristics of the trailer.
	MISCELLANEOUS - How do you calculate hitch weights? The hitch weight for conventional, bumper type hitches should be 10% to 14% of the gross weight of the vehicle. The remaining 86% to 90% of the load will be carried on the running gear. The hitch weight for 5th wheel and gooseneck type trailers should be 15% to 20% of the gross weight of the vehicle. The remaining 80% to 85% of the load will be carried on the running gear.
	MISCELLANEOUS - Is it okay to jack up my trailer? Dexter recommends that you do not jack up the trailer on the suspension components because there is always the potential for damage. Bent hangers, leaf springs, or axle tubes can cause bad axle alignment with bad tire wear resulting. Also, many trailer builders do not use Dexter hangers and we have no idea how strong these hangers may or may not be. Therefore, we take the conservative approach and recommend jacking up only on the trailer frame.
	MISCELLANEOUS - Where can I buy Dexter replacement parts that are not on your web site? Dexter Axle genuine replacement parts are available through an international network of authorized distributors.
	NEV-R-LUBE - Can I upgrade to the Nev-R-Lube option on my existing axles? No, the two bearings were moved closer together and combined into a single sealed cartridge with only one spindle journal size. This required different spindle and hub-drum designs to accommodate the Nev-R-Lube cartridge. In order to upgrade to this option it will require purchasing new axles, hubs-drums and possibly new wheels. The Nev-R-Lube option can only be used with certain wheel offsets.
	NEV-R-LUBE - How often should I grease my Nev-R-Lube bearings? The Dexter Nev-R-Lube bearings are a sealed bearing cartridge that never requires repacking with grease. However, they still need to be inspected every 12 months or 12,000 miles and can be done during your normal brake maintenance inspection process.
	TORFLEX - Can I change my Torflex start angle? No, the different start angles are achieved with different components that can't be changed once the axle is built.
	TORFLEX - Can I use 3 Torflex axles under my trailer? No, Dexter does not recommend triple Torflex applications because Torflex axles are totally independent and not equalized like a typical leaf spring set of axles. There is no ability to transfer loads from one axle to another. When traversing uneven operating surfaces such as driveway entries, railroad crossings or speed bumps, the entire load can be put onto one axle causing severe overload. It isn't reasonable to expect one axle to carry the entire load of three axles when these conditions occur, even though these instances cause only momentary over-loading.
	TORFLEX - Can I weld to my Torflex axle or move the brackets? No, the Torflex axles contain rubber cords to provide the suspension system and can be damaged by the heat generated from welding on the bracket or the tube.
	TORFLEX - What are the advantages of Torflex versus Leaf Spring axles? The Dexter Torflex axle carries a 5 year warranty vs. a 1 year warranty on our sprung axles, which demonstrates how confident we are with the Torflex suspension. There are no suspension parts to wear out (spring shackles, hangers, etc.). Rubber cushioning eliminates metal-to-metal contact. The axle capacity can be closely matched to the trailer requirements by the amount of rubber assembled in the axle. The independent suspension allows each wheel to travel totally independent from the others. A smoother ride, less sway and reduced noise is achieved with the rubber suspension. The axle can be built with various start angles to achieve desired trailer height.
	TOWING - How do I determine hitch weight? The hitch weight for conventional, bumper type hitches should be 10-14% of the gross weight of the vehicle. The remaining 86-90% of the load will be carried on the running gear. The hitch weight for 5th wheel and gooseneck type trailers should be 15-20% of the gross weight of the vehicle, with the remaining 80-85% of the load being carried on the running gear.
	WHEELS & TIRES - Can I change to aluminum wheels? Aluminum wheels are thicker through the mounting bolt area and may not leave enough stud length for proper nut engagement. Consult the wheel manufacturer for stud length and mounting face requirements and wheel nut torque.
	WHEELS & TIRES - Can I use wheels with greater offsets? Wheel offset is the distance from the mounting surface to the centerline of the tire. Dexter Axle bearing sets are designed for wheels with 0 to 1/2" inset. Exceeding this offset will shorten bearing life and may lead to dangerous bearing failure.
	WHEELS & TIRES - What is the difference between "hub" and "stud" piloted wheels? Hub-piloted wheels have a center hole machined to a close tolerance and are intended to mate with a hub having a properly sized pilot diameter. The bolt holes will be bored or stamped straight through the center disc which is designed to be fastened with either flanged nuts or a clamp ring using cone nuts. Stud-piloted wheels have a center hole which provides clearance to the hub nose. The bolt holes feature a tapered seat designed for clamping with properly matched cone nuts. The cone angle of the nut must match the cone angle around the bolt hole of the center disc. Failure to properly match these components will result in catastrophic wheel loss.
	WHEELS & TIRES - What tires can I use on these wheels? Wheels and tires must be matched. The wheel will have a label stating its rim diameter, width and contour. The tire selected must be approved by the Tire and Rim Association for use on that particular size wheel. The tire capacity selected should not exceed the capacity rating of the wheel. The tire inflation pressure must not exceed the pressure rating of the wheel. WARNING - The use of tires that are not approved for use on a wheel could result in explosive separation of the tire and wheel and could cause a serious accident.
	WHEELS & TIRES - Why do I need to re-torque my trailer wheels when I don't do that on my truck? Trailer wheels carry substantially more weight than tow vehicle wheels of the same size and see more disc flexing due to side loading stresses. It is necessary to re-torque them several times until the wheel nut torque stabilizes. This is especially true for new wheels that need to have the paint worn away at the hub mounting face and under the wheel nuts. WARNING: Be very careful to use only the recommended wheel fastening torque amount as specified for that wheel and fastener. It is possible to permanently damage a wheel that has been over torqued and may cause the loss of that wheel from the trailer.

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