We believe that you should trim and add the bare minimum of suspension lift to accommodate the widest tires feasible for your rig, and that you should construct your rig for strength and gearing to match. An aggressive stance, wide, and stable 4×4 with strong axles, robust skid plates, and body protection, adequate bump stops, and large tires instills confidence in drivers on and off the road. Trimming fenders is a critical component of this formula for trail dominance success.
Fenders hold wheels and tires in place by preventing dirt from flying uncontrolled everywhere as the wheels and tires travel over the ground. Really large tires have the disadvantage of being abrasive on your ordinary fenders, resulting in scratches and sometimes dents around the fender region, necessitating the need for fender trimming.
What Do You Need For Cutting The FendersRatchetTo tighten and loosen bolts
Dremel ToolCarving, engraving, routing, grinding, sharpening, cleaning, polishing, cutting, and sanding are just a handful of good usage.
Generally speaking, an angle grinder is a hand-held power tool that may be used for a wide variety of operations such as cutting and grinding as well as deburring and polishing.
Impact WrenchUsed for tightening and removing bolts, screws, and other fasteners. They’re a common tool in the automotive industry. The most typical application that we all encounter regularly is the removal or tightening of lug nuts while we are changing the tires on our automobiles.
Flat and Sand DiscOn an angle grinder, these discs are used.
Other Materials
Keep in mind that you must first remove the wheel with a high-lift jack or a floor jack before starting the fender cutting process.
Step 1: Make a trimming templateThe fender trimming template will act as a reference for you when it comes to determining how you want to cut your fenders.
Creating one will allow you to easily transfer the design to the remaining fenders since you will just need to mark the same lines and cuts over and over again, saving you time.
You may use an old newspaper page (or any other material of your choice) to trace the design onto and then cut out the pattern. If the old newspaper sheet does not adhere effectively to the surface after you tape it down, you have two options: either clean the car surface with a moist cloth and allow it to dry for at least three to five minutes, or use numerous adhesive tapes to secure the sheet to the vehicle surface.
Step 2: Draw a line across the area that has to be trimmedWrap the old newspaper sheet around the fender’s part and tape the side of the sheet that will be facing the inside of the fender together using electrical tape. This causes the newspaper sheet to mold into the form of your fender, making cutting the sheet much easier later on. However, since you’ll be utilizing the newspaper sheet on both sides of the door, the center of the newspaper sheet should be aligned with the edge of the door for consistency considerations.
The design on your newspaper page should be cut out so that it may serve as a guide for the cutting procedure. You may leave the pattern exactly as it is on the door’s edge, but be sure to leave a little tolerance on the wheel pattern area so that you can determine whether or not you need to make any more trimming modifications. Inevitably, when you place the fender trimming template over the fender, you’ll discover that it has an extra amount of space, and you’ll have to cut it again until it’s exactly what you want.
Step 4: Remove the fender and trim it to fitWhen trimming your 4×4, you cannot, of course, leave the fender linked to the vehicle’s body since doing so not only complicates the operation but also increases the chance of an accident. Make sure you are aware of the location of the bolts so that you can correctly remove your fender. Typically, on the bodies of 4x4s and pickup trucks, two bolts are located below them, a lot perpendicular above them, two in the lower portion of the front and one within the door just beyond the door jamb.
It is necessary to use an impact wrench to remove the bolts, but for those in difficult-to-reach regions, a ratchet or socket wrench might come in useful for the laborious but more controlled removal of the bolts.
After that, lay the fender down on a clean, level surface and begin cutting it with an angle grinder to create a new shape. Never forget to put on the right protective gear while cutting your fenders. When working with rough and sharp edges that aren’t visible to the human eye, use gloves to protect your hands. Protect your eyes with a face cover to ensure that no dirt gets into them. Using it in conjunction with a face mask can help you avoid accidentally breathing dust that may otherwise pass straight through your face shield.
To the greatest extent feasible, avoid using a Sawzall since it has a propensity to deviate from your primary cutting part, where its blade just punches through the whole fender and flaps continually.
A Dremel tool may be used, but its disadvantage is that it is sluggish to cut, thus an angle grinder is your best option for cutting in general.
It’s possible that now that your wheel and fender are out of the way, you’ll want to check more closely at the region where your wheel and fender were previously located. Normally, when your fenders are installed, there are two metal panels that are joined together. These metal sheets absorb the shock of hitting a bump or an obstruction and protrude, creating grooves or humps around the fenders when the vehicle hits them.
It is necessary to hammer each of them in order to flatten their surfaces as a consequence. In the next step, use an angle grinder to cut across the front of the fender approximately half an inch deep. This will allow you to have more room for your springs as well as to smooth off the rough edges of your fender.
Step 6: Attach the trimmed fenderIf necessary, use impact wrenches and ratchets to reattach the chopped fender to its original slot; this will ensure that it is properly reinstalled and in its proper position.
Just when you think that fender trimming may really do more damage than good to your 4×4, you’ll be shocked to learn that it can actually have the opposite effect, given that you know exactly what you’re doing and that you’re doing it for the proper reasons. As a result, we were able to debunk several common fender trimming fallacies.
Fender Trimming Is ScaryThe thought of cutting their 4×4 fenders is frightening to many users, who are concerned that they would inadvertently damage their vehicle. If you’re a newbie, this is something that you should be aware of. However, if you have become accustomed to performing basic fender trimming every now and then, you will be able to correct previous mistakes and create a cleaner, more polished appearance for your fenders, even if you are not a hardcore professional at fender trimming, as explained in the following section.
Trimming the fenders increases the likelihood of rustingThe metal portion of the fenders will be exposed to the elements of grease, dirt, and air, and as a result, many people believe that the chance of rusting is quite significant as opposed to just leaving your factory fenders alone.
In spite of the fact that they are not damaged, rust may nevertheless collect within due to the presence of dirt and moisture accumulations.
On the contrary, it is preferable to leave plenty of space between the two vehicles since, no matter what you do, the wheels will continue to move, particularly when the vehicle is rounding bends at high speeds. The difficulty with having so little room is that once the tires begin to grind against the fenders, they will ultimately dislodge the latter from their mountings and fall off.
How Far Off Should The Fender And Tire Be?The top of your tire should be no more than 3 inches over the bottom of your fender when your trailer is loaded to its maximum capacity, according to standard practice. Potholes and bumps should be avoided with this much clearance.
If you want to be accurate, you should measure the distance between the bottom of your frame and the top of your axle if you have an underslung trailer (in which the springs are located under the axle).
In order to provide proper clearance when your trailer is completely loaded, you need to add two inches to that dimension.
If you look at it from the outside, trimming your fenders is a small detail. Although it is more difficult to prevent, doing it correctly helps you avoid the issue of your fenders aggressively rubbing against your really big tires, which may cause damage to them. It will also improve the overall performance of your 4×4.
I have a question regarding the safe distance (gap) between fifth-wheel RV tires. I’ve looked at various tandem-axle trailers, and the distance between the tires varies. The distance between our fifth-wheel tires is about 1½ inches, and that seems to be too close together.
Our RV is a 2015 Redwood 38RL that we purchased in February 2016. It is a beautiful, spacious trailer that my wife and I enjoy very much. We had an issue last December when a bolt came out of the undercarriage, causing extensive damage that required the replacement of the rear axle, a portion of the frame and all four tires.
I don’t recall how close together the tires were prior to the repairs, but now they seem too close. Should I be concerned?
Robert Lorbeer | Prescott, Arizona
“A miss is as good as a mile,” Robert, and as long as your RV’s tires don’t show any evidence of contact-related damage, you’re good. There are different tire-to-tire spacings because there are many different tire sizes and suspension configurations in use on different size and model trailers.
A trailer suspension primarily allows a tire to move vertically with the suspension travel, but there’s also a small amount of fore-and-aft movement that takes place. However, there’s not enough fore-and-aft movement to cause tires to rub when they’re 1½ inches apart at rest.
If a suspension were so worn out that it allowed that much flopping around, it would need some serious repair, and it’s likely the tires would be failing because they’d be seriously out of alignment.
Make sure the shackles and other components are in good shape, and your setup is probably fine.
More Tire Clearance
I have a 34-foot Keystone Tailgator toy hauler with only 2 to 3 inches of clearance between the fifth-wheel’s tires and the top of the fender well. The tires were rubbing the top, and the factory had left a screw above the rear tires on both sides. On the right side, the screw punctured the tire, and the tire shredded on a recent trip.
When I figured this out, I had my springs put on top of the axles instead of under them. This raised the trailer about 5½ inches. The sewer dump was also very low, and the front of the trailer was high when hooked to my truck. This fixed all of that.
What is your opinion on having this done? It cost me only $432.
Roger Meacham | San Angelo, Texas
That seems like a pretty good pricing deal, Roger, and the clearance-problem solution should work well. Doing a spring and axle flip is a solid, reliable way to raise the trailer a few inches. Some people express concern that this may make a trailer less stable, but in fact it would take a much greater lift to adversely affect handling.
A few inches will raise the rig’s center of gravity a bit, but not enough to cause any harm, unless you’re in the habit of speeding around corners, for example.
Exterior Polish
I read Marlyn Demeter’s “Fiberglass Cleanup Redux” letter in July’s RV Clinic about repairing the finish on the front end of a trailer. My brother-in-law used a product on the sides of his motorhome. It looked great, so I tried some on the front of our fifth-wheel, which is exposed to the sun from dawn to 3 p.m. daily. Wow, it looks like new. It was designed for boats but works on fiberglass RVs. The product is Poli Glow, and it can be ordered at 800-922-5013 or on www.poliglow-int.com. I hope this helps.
David Rayles | Vevay, Indiana
Thank you for the recommendation, David. There are a number of good products for restoring an RV’s fiberglass finish on the market, and it’s good to hear that Poli Glow worked for you. We’re passing this on to our readers, as some may find it very useful.
I read September’s “Half-Ton Towables” article on fifth-wheel towing with a full-size pickup. I have a 2014 Toyota Tundra and tow a 2013 28-foot Palomino Puma.
I have had the truck and trailer weighed with my wife and me in the truck and the trailer loaded for a trip. The truck weighs 5,220 pounds, and the trailer was weighed separately at 8,460 pounds. Dry weight on the sticker for the trailer is 6,922 pounds, and cargo capacity is 2,871 pounds.
If I add the empty weight of the trailer and the cargo weight, that comes to 9,793 pounds. According to Toyota’s owner’s guide, the truck will pull 12,300 pounds in the bed.
Is the weight of the truck included in that total towing capacity from the manufacturer, or is it just the weight of the trailer? The tongue weighs 1,086 pounds.
This has nothing to do with towing weight, but the brakes Toyota put on the Tundra did not hold up, even though I have the towing package.
Toyota replaced two sets of front brake pads under warranty. I have since changed all four wheels to Power Stop rotors and pads.
Bill Allender | North Hills, California
We address the matter of how to use the gross vehicle weight rating (gvwr), gross axle weight rating (gawr), gross combination weight rating (gcwr) and other figures relating to setting up or analyzing a tow rig and trailer combination on a regular basis in these pages and on our website. The question keeps arising, so we’ll take another shot at it here.
First, you didn’t provide body style, engine, axle ratio and other pertinent towing information, so some of our figures will be approximate, based on Toyota’s 2014 Tundra published information. Your truck is rated for a maximum tow rating of 10,400 pounds and ranges down to 9,000 pounds, based on the variables mentioned above.
To determine the true towing capacity for your truck, you’ll need to deduct the weight of the truck, passengers, accessories, fuel and cargo from the gcwr, which could be as much as 16,000 pounds, depending on factory equipment.
If your truck has the highest gcwr, you should be in good shape regarding your trailer’s 8,460-pound weight.
Regarding your frequent brake-pad replacement, we haven’t heard any other reader reports of this situation, so it doesn’t seem to be a significant problem with Tundra trucks. If the brake control is not adjusted properly, the trailer will not do its share of braking and that could cause premature pad wear. This is also dangerous, because in an emergency you won’t have the full potential trailer braking to stop the combo.
I’d recommend taking the truck and trailer to a service center to check the brake-control adjustment and inspect the trailer brakes for proper operation. This may well eliminate
or significantly reduce premature brake wear.
08/15/2014
Requirements for parameters, dimensions, technical requirements for trailers for passenger cars are established by OST 37.001. 220-80 "Trailers for cars".
This standard applies to all types of trailers intended for towing by cars and minibuses on the roads of the general network of the USSR.
This standard does not apply to trailers whose design specifications were approved prior to the introduction of this standard.
The main terms used in the standard and their definition are given in the reference appendix.
1. PARAMETERS AND DIMENSIONS
1.1. The total design weight of the trailer must not exceed the permitted by the manufacturer of the traction vehicle, must not be more than the curb weight of the traction vehicle and exceed 1800 kg.
1.2. The total structural weight of the trailer without brakes must not exceed the permitted by the manufacturer of the traction vehicle and must not be more than half of the curb weight of the traction vehicle.
1.3. The vertical static load in the center of the ball joint of the coupling device in any weight condition of the trailer must correspond to the value permitted by the manufacturer of the traction vehicle, but must not be less than 240 N (25 kgf) and more than 980 N (100 kgf).
1.4. The length of the trailer must not be more than 1.5 times the length of the main traction vehicle or more than 8 m.
1.5. The width of the trailer must not exceed the width of the main traction vehicle by more than 200 mm on each side and must not exceed 2.3 m.
1.6. The height of the trailer must not be more than 1.8 of the trailer gauge or more than 3m.
1.7. The center of gravity of a loaded trailer must be located in such a way that the ratio of the height of the center of gravity to the gauge of the trailer wheels is no more than 0.725.
1.8. The ground clearance of the trailer must not be less than the ground clearance of the main traction vehicle.
2. TECHNICAL REQUIREMENTS
2.1. General requirements
2.1.1. Trailers must be single-axle, it is allowed to use a paired axle.
2.1 2 A trailer with a horizontal inner floor, mounted on a horizontal surface, must have a load on one side of the tire(s) of not more than 55% of its gross weight.
2 1.3. The design of the trailer must be designed for movement as part of a road train with a full design mass at a maximum speed permitted by manufacturers of traction vehicles.
2.1.4. The design and dimensions of the drawbar (frame) of the trailer must ensure the possibility of its deviation relative to the coupling ball installed on the vehicle, at the angles provided for by OST 37.001.096-77.
2.1.5. Trailers must be equipped with two non-removable safety chains (cables), which, in the event of an emergency break (breakage) of the towing device, must not allow the drawbar to touch the road surface, while ensuring trailer control.
2.1.6. Trailers must have two wheel chocks ("shoes").
2.1.7. Trailers must have space for jacking.
2.1.8. The trailer parking brake control must be removable and located on the right side in front of the drawbar (frame).
2.1.9. Trailers must be equipped with under-wheel protective devices (fenders, mudguards) if body parts do not perform the function of this device.
2.1.10. Materials used for the manufacture of trailers must have resistance to fire from water, fuel and oils not lower than the resistance of materials for parts and assemblies of a similar purpose of the main traction vehicle.
2.1.11. Painting of trailers and control of the appearance of the coating in accordance with GOST 7593-80.
2.1.12. The trailer must have a climatic modification in accordance with GOST 15150-69corresponding to the climatic version of the main traction vehicle, and must be designed for storage conditions in open areas.
2.1.13. The service life of the trailer in accordance with the purpose and operating conditions are regulated by regulatory and technical documentation approved in the prescribed manner.
2.2. REQUIREMENTS FOR SYSTEMS, ASSEMBLY AND UNITS
2.2.1. Trailer braking systems must comply with the requirements of OST 37.001.016 70.
2.2.2. The locking device for coupling with a traction vehicle must comply with the requirements of OST 37.
001.096-77.
2.2.3. Electrical equipment, external lighting and signal devices must comply with the requirements of GOST 3940-71. GOST 8769-75, GOST 10984-74 and GOST 20961-75.
2.2.4. Trailers must have brackets (or a place) for attaching a license plate in accordance with GOST 3207-77.
2.2.5. To connect to the vehicle's electrical system, the trailer must have a plug in accordance with GOST 9209-76 with a connecting cable.
2.2.6. Trailers must have support legs that ensure the stability of the trailer in the uncoupled state and do not impair the cross-country ability of the road train.
With a vertical static load from the trailer locking device of more than 390 N (40 kgf), the front support leg must be equipped with a lifting-lowering mechanism that ensures that the locking device is installed in the position necessary for coupling (uncoupling). When the mechanism is manually driven, the force on the handle should not exceed 118N (12 kgf).
3. COMPLETE
3.
1. Trailers equipped with tires not unified with the main traction vehicle must have a spare wheel and a device for its fastening.
3.2. Trailers must be accompanied by the necessary tools and accessories if the set of tools and accessories of the main traction vehicle is not sufficient to service the trailer.
4. MARKING
4.1. Trailers must have a nameplate and markings in accordance with industry normative and technical documentation.
4.2. Trailers must have an additional plate near the locking device in accordance with GOST 12971-67 indicating the full design mass of the trailer; the value of the maximum static load on the coupling ball.
Terms and definitions adopted in this standard
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Tags: Design and manufacture of trailers
Maintenance and repair of trailers Do you need category E?
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Main: the choice of a trailer starts with a boat (boat)!!! You need to select a trailer exclusively for your boat or boat. There is no universal trailer (trailer) suitable for all types and sizes of boats (boats). For example, if your trailer is designed to carry a four-meter boat, then you will have to buy a new one for a six-meter boat. The length of the vessel and its mass with all the equipment transported are the two initial indicators for choosing a trailer (trailer).
Of course, for most Moormans, a boat trailer is not an essential item. Indeed: a boat (boat) can be “registered” once and for all at a coastal boat parking lot, come there at any convenient moment, start the engine and hit the road.
However, enthusiasts have not yet died out, ready to do anything just to explore new, unexplored water areas, which can be reached by the usual navigation method, by water - either long, or expensive, or simply impossible.
Among the additional arguments in favor of purchasing a trailer (trailer), such as the ability to raise the vessel to the shore every time after returning from the water (which increases its durability and facilitates maintenance), as well as store it closer to home - for example, on guarded car park or garage, which is especially valuable in winter.
A boat trailer is a vehicle without an engine designed to transport water equipment (boat, boat, jet ski).
The boat trailer is used in conjunction with a tractor vehicle, which tows the boat trailer.
The boat trailer differs from other trailers in its design, thanks to which it is easy to load a boat onto it and launch a boat from it.
The design of the trailer (trailer) is a metal frame with cradles installed on it.
Rollers can be used as lodgements in the structure. There are trailers with a combined type that have both lodgements and rollers. The frame of the trailer (trailer) goes into a drawbar (horizontal arm in front of the boat trailer), on which the hitch assembly and winch are located.
Adjustable.
The same trailer model can fit several types of boats (boats).
And then the formula:
Trailer length = boat length + 0.4 m (per engine)
Also consider that the dimensions of the trailer correspond to the intended storage location.
The material is important, or rather the material of the bottom of the boat (boat). It is very important. If the bottom of the boat is made of a hard material such as plastic, a roller trailer will do. If the bottom of the boat is made of PVC, there is nothing better than a skid trailer.
And the rollers will break such a boat in the process of several transportations.
It is advisable to choose trailers with plastic fenders rather than metal fenders. While driving, stones and sand flying from under the wheels deform the metal coating, which ultimately leads to corrosion. And replacing such wings is a laborious and expensive process, which cannot be said about plastic. In addition, durable plastic fenders eliminate the possibility of damage to the boat itself during loading or unloading.
Since light trailers are designed to be fully or partially submerged in water, their frame must be protected from corrosion. It is better if the metal is galvanized, both inside and outside the elements of the supporting structure. Electricity, accordingly, must be waterproof.
Overloading is the main cause of failure of trailers (trailers). And this happens only through the fault of the owner himself, who does not know enough about the permitted weight.
Trailers can be single or double axle. A trailer (trailer) with two axles, the distance between which is less than 1 meter, is called a twin axle trailer.
The suspension of boat trailers is not fundamentally different from the suspension of other trailers. On single-axle trailers (trailers), the following types of suspensions are most widely used:
Attention! It is mandatory to register the trailer with the traffic police.
When choosing and buying a trailer (trailer), remember that the presence of category "B" is enough to drive a car with a trailer, the mass of which does not exceed 750 kg.
If you need to transport large loads, you need to take care of opening category "E".
The right to drive a car with a trailer is divided into categories depending on the mass of the constituent parts of this road train. So, to drive a car with a trailer weighing more than 750 kg, in principle, category “E” is required. However, if two conditions are met: the total gross weight of the vehicle and trailer does not exceed 3,500 kg and the gross weight of the trailer does not exceed the curb weight of the vehicle, then category "B" is sufficient. Otherwise, category "E" is required, while the gross weight of the trailer for a car should not exceed 3500 kg.
Trailer insurance is also a constant stumbling block between motorists and traffic cops. Until recently, OSAGO on a trailer was considered mandatory, and the arguments of car enthusiasts that the trailer would not go by itself without a car were not taken into account by the authorities. The situation changed with the introduction of a new law dated March 01, 2008. According to the new rules, OSAGO is not required for a light trailer.
Transporting a boat (boat) can be a complicated and dangerous undertaking, but following a few simple tips, it can be a relatively simple process that is not only safe, but also very easy.
This guarantees the safety of transportation.
Remember! The road does not forgive mistakes.
In conclusion:
Parameters, dimensions and general technical requirements OST 37.001.220-80.
This standard applies to all types of trailers intended for towing by cars and minibuses on the roads of Russia. The standard does not apply to trailers, technical specifications for the design of which were approved before the introduction of this standard. The main terms used in the standard and their definition are given in the reference appendix.
TECHNICAL REQUIREMENTS 
1.13. The service life of the trailer in accordance with the purpose and operating conditions is regulated by the regulatory and technical documentation approved in the prescribed manner. 2.2.6. Trailers must have support legs that ensure the stability of the trailer in the uncoupled state and do not impair the cross-country ability of the road train.
With a vertical static load from the trailer locking device of more than 390 N (40 kgf), the front support leg must be equipped with a raise-lower mechanism. This mechanism ensures the installation of the locking device in the position required for coupling (uncoupling). When the mechanism is manually driven, the force on the handle should not exceed 118 N (12 kgf).
