The five best modifications . . . to leave off your expedition vehicle

Expedition travel is a different universe than weekend four-wheeling. When you’re just out for a few days near home—camping, challenging a few trails—breaking down is no more than an inconvenience. But if you’ve embarked on a long journey far from familiar territory, perhaps in another country or on another continent, a breakdown can endanger the trip—or even your safety if you’re traveling solo and are tens or hundreds of miles from assistance. For journeys such as this, your priorities regarding vehicle modifications and accessories need to change, from an emphasis on maximum 4WD performance (and, let’s be honest, maximum looks) to reliability and durability. A lot of the products that enhance the former can seriously impact the latter. Here are a few of the most important.

Big tires. Everyone loves the look of big, aggressive tires on a 4x4, and in certain situations they have advantages in ground clearance, traction, and the ability to successfully climb ledges. But big, heavy tires extract a heavy price. They put massive additional stress on your suspension, steering components, and bearings. They hurt fuel economy and retard acceleration—and if you install higher-ratio differential gears in an attempt to compensate for these downsides, you’ll simply weaken the pinion gear, which has to be reduced in size to gain the higher ratio. Larger-diameter and heavier tires also increase braking distances. Remember that Land Rovers conquered Africa on skinny 7.50 x 16 tires, and Land Cruisers conquered Australia on the same size. Besides, if you destroy one of your 38s in Botswana I guarantee you won’t find a replacement in Maun. They know better there. For more details on the downsides of big tires, see here.

Installing higher ratio ring and pinion gears results in a smaller, weaker pinion gear.

Big suspension lift. As with tires, there are some advantages to a raised suspension for rock crawling or mud bogging. Not on an expedition. You want to keep your center of gravity as low as possible to ensure maximum fuel economy and safe handling while carrying the equipment and rations needed for a long journey. Big suspension lifts increase angles on rod ends and driveshaft joints, leading to premature wear. You’ve probably seen photos of the Camel Trophy Land Rovers that challenged some of the toughest terrain on the planet—they all rode on stock-height suspension. If you really think you need some lift, keep it to a couple of inches. The expedition experts at ARB know this—their Old Man Emu suspension kits are all in the two-inch range.

Race shocks. Along with a suspension lift, many owners install long-travel shocks modeled after racing versions, with all-metal heim-joint ends, external-bypass tubes, and remote reservoirs. Shocks like this are designed to deal with the kind of high-speed, high-amplitude movement common in off-road races—exactly what you’re not going to be doing on a long journey in a loaded vehicle. You’re better off using a simple shock with enough oil capacity to stay cool after a full day of driving over washboard or rutted roads and trails. Standard rubber bushings last longer and are far easier to replace than heim joints, and help dampen road vibrations. Exposed chrome shafts quickly become sandblasted in the bush; they should be shielded or completely covered with a sheath or bellows. 

The best expedition shock I’ve ever used is the Koni Heavy Track Raid, an utterly boring-looking thing next to the racer models, but with a huge oil capacity capable of soaking up mile after mile of abuse under a fully loaded Land Rover 110. ARB’s (Old Man Emu) BP51 is another excellent shock, employing internal bypass valves that allow adjustment of both compression and rebound without the exposed bits of external pypass tubes. Some BP51 models, it appears, come with heim joints; I’d avoid those. Sadly neither of these shocks is available for my FJ40 or I’d have them on it (although the standard OME Nitrocharger has performed well for me for decades).

The Koni Heavy Track Raid relies on robust twin-tube design and massive oil volume to handle torturous conditions.

Wheel spacers. A wheel spacer is a disk—usually aluminum—that fits between the hub and the wheel to increase track width and reduce lateral load transfer, which can fractionally help handling and stability. They give your truck a more aggressive look, too. Unfortunately, they also put significant extra stress on wheel bearings, since as you move the wheel farther away from the bearing you’re essentially lengthening a very strong lever. You’re also increasing the scrub radius, which is the distance between where the pivot point of the kingpin intersects the ground and the center of the tread, as well as increasing the kingpin offset. All of this affects the steering and suspension negatively, and will wear components you do not want to have to replace in a spot where “Amazon” only refers to a large river. 

Every time I criticize wheel spacers I get emails from guys (you know who you are) who’ve had them on for X-hundred thousand miles and never had a problem. I don’t doubt this. But physics is physics, and putting extra leverage on your wheel bearings and steering components does them no good, period. (I know a guy who smoked two packs of cigarettes a day and lived to 80, too. Doesn’t prove it’s a good idea.)

“High-performance” air intakes. Intake systems that replace the stock air filter with one designed—or at least hyped—to produce more horsepower are frequently much worse at actually filtering air, and are often more vulnerable to water intrusion during a crossing. Those advertised horsepower gains are measured on a dyno—about as far from expedition reality as possible. The truth is, most factory intake systems are carefully routed to ingest cold outside air while minimizing the danger of water ingress. You can, if you choose, install a snorkel, which contrary to belief does not automatically turn your vehicle into a submarine, but does help get the intake above some ground-level dust. 

Roof rack. Okay, I said five, but here’s a bonus. Do without a roof rack if you can. Ah, but what about the Camel Trophy Land Rovers I just mentioned? They looked awesome under those racks piled high with jerry cans and PelicanPelican cases, right? True, but, first, the CT vehicles usually had two team members plus two journalists inside; they were operating in extremely remote terrain, and and simply had to carry extra gear on the roof. More important, those vehicles all too frequently ended up on their sides during demanding special tasks. You don’t want to do that, because you won’t have 15 other Camel Trophy vehicles to help you get back on all four wheels. 

Excess roof loads negatively affect handling and fuel economy, and everything strapped up there is vulnerable to casual theft. It’s even bad for braking: Weight up high tends to pitch the vehicle forward under braking, unloading the rear tires. If you absolutely need a roof rack, keep the load as light as possible—the weight of the rack itself plus, say, a tent is about maximum for safety’s sake. Some of the current minimalist aluminum racks from Front Runner and ARB don’t add much mass or bulk themselves, as long as they’re not loaded up with 300 pounds worth of jerry cans and Hi-Lifts and solar hot shower systems.

Remember, on a long, remote journey, reliability should be your number one through five priority. Add on all the accessories you like that won’t affect that, but the best approach to most critical driveline components is to stay as close to stock as possible.

Proof in the pudding: We successfully negotiated the Abu Moharek sand sea in three Land cruisers with 1) near-stock-size tires, 2) stock suspension, 3) factory (raised) air intakes, 4) no wheel spacers, and 5) lightly loaded roof racks.

(A version of this article first appeared in Tread magazine.)