Top 5 Mods For Off-Road Diesels


The United States of America encompasses more than 3.5 million square miles of land mass – no small amount of territory. And though most drivers are content to travel along paved roads and highways, making their way from suburbia to the city and back, it’s the adventurous types who bring some fun and madness to the diesel world.

Top5offroaddiesel_12While most folks go out and purchase a diesel for peak performance in terms of towing and hauling, it’s little wonder how so many of these trucks wind up lifted, kitted out, and ready to take on Mother Nature. High ground clearance, solid axles, and the easy potential to swap out for larger tires are just a handful of reasons that diesel trucks get made into killer 4x4s, no matter the make or model.

Major diesel truckmakers like Ford, GM, and Chrysler sometimes capitalize on the off-road passion through special packages; Ford has the FX4 option, GM has the Z71 option, and Chrysler has the TRX4 option. All of these packages ride the edge of offering a miniscule improvement for off-road use, typically through higher-performing shock absorbers, some skid plates, and all-terrain tires like Toyo Open Country A/Ts or Goodyear Wrangler A/Ts. But these are hardly the only components needed to prepare an epic rig.

In this piece, we will discuss what we consider the top five essential modifications needed to take a stock diesel truck and make it into an off-pavement badass. Follow along below and keep track – you may find yourself in need of changing one or more aspects on your own pickup to make it perfect for adventure.

5. Tires And Wheels


As one of the easiest and most cost-effective ways to improve off-road performance, wheels and tires occupy a special section of off-road mods, as they affect traction of the vehicle over different types of terrain. Snow, dirt, sand, mud, and rocks all present different challenges to vehicles, and different tires work in certain situations better than others, so it’s important that truck owners determine which type of tire best suits his or her needs.

Top5offroaddiesel_9Off-road tires break down into two categories: all-terrain and mud-terrain. All-terrains, as the name implies, are meant to handle a variety of surfaces competently, while also providing favorable performance on asphalt. These types of tires typically use stiffer sidewalls, and have tread patterns with wider gaps between the tread blocks to aid in self-cleaning. These wider gaps are apt to make more noise than a regular all-season tire, however, and they’re more prone to cupping (scalloping that occurs in tread blocks from weakened suspension and exposure to harsh terrain).

All-terrains are best suited to trucks that mix business with pleasure, so if a diesel truck fulfills roles as both a daily driver and a “weekend toy,” picking up all-terrains is a solid choice. There are dozens to choose from, including models by Mickey Thompson, BF Goodrich, Hankook, Toyo, Nitto, Goodyear, and many more.

One rung up the performance ladder are mud-terrains, also known as M&S (mud & snow) tires. Mud-terrains are better equipped to deal with harsh off-road environments almost exclusively, but come at the cost of on-road longevity. Notable traits of mud-terrains include softer rubber compounds that allow for greater surface area when underinflated, thus increasing grip, as well as gaps between the tread blocks that are wider than those of all-terrains, which minimize the buildup of debris and loss of traction.

A lot of the aforementioned companies also offer mud-terrains, with varying degrees of utility and user satisfaction. We suggest that you do some research online and make a choice that will best suit your needs: a tire for everywhere, or a tire for almost exclusive off-road use?

4. Engine And Exhaust


The belly of the beast: the engine and the exhaust. It’s here where things can quickly get over one’s head and spiral out of control, with one modification affecting another and leading to budgeting issues. Again, it’s important to take into account what you want from your vehicle before you get ahead of yourself. But making these modifications definitely has the potential to ramp up the off-road fun.

Top5offroaddiesel_6That doesn’t mean there aren’t a few modifications that can be done without so much muss and fuss. Air filters and intakes, for example, are one component of the engine that, from the factory, come pretty bland in terms of performance. They can be easily modified using a cold air intake kit from the likes of K&N, AIRAID, aFe Power, and many more. These will improve airflow to the engine by getting rid of inefficient tubing and resonators, adding horsepower and torque (as well as more engine noise) to a vehicle. On top of this, cold air intake kits take virtually little time to install, and are usually non-permanent if the owner wishes to restore the truck to its factory setup.

Tuning is another method that is popular nowadays. With the addition of ECUs to automobiles came electronic parameters that factory engineers determined were the most optimal for the everyday owner. By tapping into the ECU and remapping or reprogramming it, more power and torque can be “unlocked” to suit a user’s needs. Within the world of tuning, there are two approaches: flash, and on-the-fly. Flash tuning involves having a tune programmed into the ECU that stays on all the time, whereas on-the-fly tuning can be programmed and controlled at any time using a handheld device, which can be mounted inside the cabin or stowed away for later use.

In either approach, several programmers offer “canned” (pre-programmed) tunes that apply to a particular make and model, determined by extensive testing done by an aftermarket company – Edge Products, EFILive, SCT, Bully Dog, etc. – on existing makes and models. For the more electronically-inclined, there are tips and tricks on forums like,, and to help create specific, one-off tunes for a single truck.

3. Suspension


Whether held at stock height or lifted to the clouds, diesel trucks make a distinct statement with each and every suspension setup. Lifting a truck carries with it some special considerations, including factors like ride comfort, center of gravity, and weight, just to name a few. As it concerns off-roading, suspension comes in several forms, using links, coilovers, bypasses, airbags, cantilevers, and more.

Top5offroaddiesel_7For desert areas with plenty of dirt and sand, you can run either leaf springs or linked suspension setups. Leaf springs are the industry standard on Ford and GM models, while Ram has introduced linked suspension to contemporary models. We won’t get into the debate on leafs versus links here; we’ll only offer what we think are some good bolt-on mods that can work on either setup.

Regarding leaf-spring applications, a popular mod is an add-a-leaf kit or replacement of the entire leaf pack. This helps off-road performance in that stock setups are geared toward an average user, while add-a-leaf kits and leaf pack replacements are geared toward off-road enthusiasts. Linked suspension trucks can benefit from installing purpose-built springs, which will affect the spring rate and vary up the cushioning effect to make them either stiffer or softer across different terrain types.

Shock absorbers come in a variety of configurations and require some additional thought before purchasing. Consider how much you like or don’t like the current ride comfort of your truck, and then seek out the shocks that will offer you what you want, whether it’s a good balance of on- and off-road utility, or pure off-road performance. Companies like BilsteinFOX Racing, King, Sway-A-Way, KORE, Icon Vehicle Dynamics, and more all offer top-tier kits and components to enhance off-road driving.

2. Accessories


Accessories are the icing on the cake; once everything else has been addressed, these are the products that add an extra layer of utility or just plain look good to the owner. For our purposes, we’ll look at three accessories that fulfill the former category: lights, winches, and storage racks.

Top5offroaddiesel_4Lights are an important add-on for off-roaders. Visibility when off-roading can drop significantly at night, when shadows, blind corners, and crests create an added layer of danger to the experience. Being able to see others (as well as be seen by others) mitigates the risk of crashing, pure and simple. Light bars, square lamps, strobes, and other options give sight back to the driver when the sun sets. The placement of these lights is equally as important as having them in the first place.

Two main types of lights, flood and spot, dictate the way light is projected. Flood lights spread a beam of light from side to side, and are beneficial to heightening situational awareness like outlying trees and bushes. Spotlights shoot light in a concentrated pattern, focusing on faraway objects and horizons where there may be a dropoff or crest that looks hazardous. In any case, it’s good to have both installed on a truck. Companies like KC HiLiTES, Rigid Industries, and others make these products in varying price indexes to suit different budgets.

Top5offroaddiesel_1Winches make life easier for everyone when the going gets rough. Even the most skilled driver with a tricked-out truck can manage to become stuck, and having a winch on hand makes the extraction far more easy to deal with. Most off-road rigs will have a winch installed in the front, as chances are that going forward is the best route in a given situation. On the flipside, a rear-mounted winch takes care of a last-resort situation, where going forward is impossible (like a cliff). WARN, GranatelliMile Marker, Superwinch, Smittybilt, and others are good companies to consider for winches and winch accessories.

Storage racks carry all the gear you don’t want inside the cab. Tools, rope, straps, high-lift jacks, and other pieces of equipment can take up a lot of room, and storage racks serve to place these items out of the way when not in use, while keeping them from flying off during driving. Wilco Offroad, Body Armor 4×4, Addictive Desert Designs (ADD), and more have storage racks to fit trucks.

1. Driveline


All of these modifications to a truck may be fine and dandy, but the sheer amount of weight they add can do a number on the driveline. Without proper forethought, a stressed-out truck can have its driveshafts snap under load, and at that point it might as well be a four-ton paperweight.

Top5offroaddiesel_3In the interest of bulking up the pickup to deal with all the extra weight, modifications must be applied to the driveline to ensure it can still carry out basic functions like driving and steering. Driveshafts should be swapped out for sturdier units with thicker walls and chromoly construction. Axles can be increased from a three-quarter-ton to a one-ton housing, featuring thicker axle shafts and bigger bearings.

Differentials can be given different gear sets to make more low-end power, as well as beefed up into locking or limited-slip functions that offer increased traction. Transfer cases are a little different, however; all models, like the NP205, Atlas II, and Marlin Crawler, have their adherents and detractors, so it behooves you to research the facts and figures of these parts before settling on the right one. J.E. Reel Driveline, Advance Adapters, Currie Enterprises, Yukon Gear & Axle, and more all offer top-tier components – as well as great advice – for the driveline category.

Off-roading is far from serious business. It’s supposed to be fun, first and foremost, but doing it right takes a reasoned and well-informed approach. Which of these categories do you want to address on your rig? Let us know in the comments below.



About the author

David Chick

David Chick comes to us ready for adventure. With passions that span clean and fast Corvettes all the way to down and dirty off-road vehicles (just ask him about his dream Jurassic Park Explorer), David's eclectic tastes lend well to his multiple automotive writing passions.
Read My Articles

Enlist in the Diesel Army newsletter.

Receive the latest newsletter with the content you love from Diesel Army, directly to your inbox, absolutely FREE!

Free WordPress Themes

We will safeguard your e-mail and only send content you request.

Diesel Army


We'll send you the most exciting Diesel articles, news, truck features, and videos every week.

Diesel Army


We will safeguard your e-mail and only send content you request.

Diesel Army

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

Off road, Jeeps, 4x4s
Engine Tech
Drag Racing

Diesel Army

Thank you for your subscription.

Subscribe to more FREE Online Magazines!

We think you might like...

  • ORX Off road, Jeeps, 4x4s
  • EngineLabs Engine Tech
  • Dragzine Drag Racing

Diesel Army


Thank you for your subscription.

Thank you for your subscription.

Diesel Army

Thank you for your subscription.

Thank you for your subscription.