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Lifted Trucks Problems and Solutions:
The Good, The Bad, & The Lifted
Lifted trucks are cool. Sky-high trucks are even cooler. Driving a lifted truck makes you feel like king of the road. You can see above all those road logs hauling soccer families, and you are able to see that sport compact that wrecked with the big rig, far up ahead, way before you even get into the mix. Lifted trucks draw attention from everyone on the road and act as giant billboards at local shows, putting that paintjob high up in the sky for everyone to see. Tall trucks command respect on the open highway, and most people will get out of your way once they feel the heat of your headlights on the backs of their necks. Lifted trucks are also functional. They allow people to traverse rough terrain safely and take the occupants to places far from the city to enjoy places of calm. These purpose-built rigs are freedom machines.
But with that freedom comes some drawbacks that need to be addressed in order for a lifted truck to work reliably and effectively as a daily driver. How high should a daily driver be? Is it practical to drive a 16-inch lifted truck on the street? And if you are going to lift to the extreme, what can you do to make your driving experience a more livable one? We'll show you some of the common problems associated with lifted trucks and throw a few solutions your way so you can determine if living with a towering four-wheeled high-rise is for you.
Brakes are often one of the most overlooked upgrades when installing larger tires. The big meats that inevitably find their way onto a truck after a lift will compromise your stock braking system. The increased leverage of the bigger tires, along with the heavier rotating mass, will quickly overwhelm the stock system, leading to overheating, premature pad and rotor wear, increased stopping distance, and minimal, if any, reserve braking power when loaded down or towing.
Fortunately, for those of us who love big trucks, there are many companies out there offering big-brake upgrade kits. These kits are meant for use with larger-diameter wheels, and include larger and thicker drilled or slotted rotors, high-performance brake pads, and multi-piston calipers. Big-brake kits have excellent pedal feel, offer improved reserve braking, and are resistant to fade-causing heat buildup. Companies such as Baer, Brembo, Stainless Steel Brakes, and Stillen have the most popular truck applications covered. Many kits will include longer stainless steel-braided brake lines that will account for the extra height and suspension travel of the lift kit. Stainless steel lines also improve braking performance by deforming less under heavy braking, and they will be more resistant to rupture.
When altering a truck's suspension to make it higher, the vehicle's frame and body is moved up and away from the differentials. This causes the driveshaft angles to become extreme, often causing bind, premature wear, and nasty vibrations. On lifted IFS trucks, the CV joints also become an issue, especially on trucks that have a wider track, and are lifted with a longer coil spring or cranked torsion bars. Many aftermarket lift kits provide CV spacers to move the stock axle outward, effectively lengthening it, but spacers aren't necessarily the best answer for the long haul.
For leaf sprung, solid-axled vehicles, pinion wedges should be installed between the axle and spring pack to compensate for the driveshaft angle by rotating the differential housing up, making for a clean pinion angle on the differential side. Often, this is not as easy to accomplish with the transmission or transfer case side of the driveshaft, and your U-joint-style driveshaft is best tossed for a custom unit, using a double cardan or CV joint that can run smoothly at higher angles. Custom-length CV axles are also a better bet for any lift kit, especially those that offer increased wheel travel over stock, and recommend that spacers should be used in conjunction with stock axles. The last thing you want is to blow a joint in the middle of nowhere, especially on newer vehicles that have live front axles in place of traditional hubs, and have no means of disengaging the front axle.
A major drawback to upping the tire size is getting power from your engine to the ground. Installing different-sized tires from stock will effectively change your truck's gear ratio. With a bigger tire, the truck will feel like it is geared higher (numerically lower), which is great for highway cruising, but not for low-end grunt, off-the-line acceleration, or passing power.
To bring your truck back to stock performance, it is important to re-gear the truck accordingly. A simple calculation will tell you what gear ratio would get you back to your stock equivalent. The calculation is your new tire diameter, divided by your old tire diameter, multiplied by your old axle ratio, will equal your new axle ratio (new tire diameter/old tire diameter x current axle ratio = new axle ratio). For towing or performance, you would want the next gear ratio lower than the stock equivalent. So, if our '95 project Silverado had 30-inch tires stock, and a 3.73 axle ratio, that calculation would tell us we need a 4.103 (which rounds off to the readily available 4.10) gear ratio to get us back to stock. The next lowest ratio from a 4.10 is the 4.56, which should be selected for towing and performance. Needless to say, we went with 4.56s on the Chevy. Because of the extra weight associated with off-road tires, we recommend always going with a performance-minded gear ratio for any tire size above 35 inches. And, keep in mind that 4x4s need both the front and rear diff re-geared to the same ratio.
Once the truck is up in the air and outfitted with those aggressive off-road lugs, you will notice deterioration of on-street handling. But, the pavement-shunning donuts are not the only cause of sloppy steering. The vehicle may exhibit bumpsteer, wandering, and slowly react to the driver's inputs. All of the symptoms can be traced back to two types of issues: steering system overburdened by the wheels, and tires or improper steering geometry.
Sometimes custom steering, including equal length setups, is required to cure a lifted truck's steering ills. But, even on the most basic live-axle truck, it is important for the tie rod to be parallel to the axle and the trac bar and Panhard bar to be parallel to each other. Sometimes, an extended heavy-duty pitman arm can be used to keep good steering geometry. With really big tires, the stock steering system may be woefully inadequate, and steering assist, such as a hydraulic ram, may be necessary to help turn the meats. We also recommend religious maintenance of wheel bearings, and the addition of steering stabilizers to keep the frontend working properly. It is important to remember that your 3-1/2-ton rolling barge is no longer as capable in emergency avoidance maneuvers as it was when it was stock, and is by no means a sportscar. Your driving style should be tailored accordingly.
If you have ever ridden in, or driven a lowered truck, you are well aware of that lifted Super Duty coming up from behind with the headlights shining clear above your cab and lighting up the night sky ahead of you, as if you had a roof-mounted lightbar attached to your road grater. Chances are, that Super Duty pilot is driving by Braille at night, because he can't see a thing on the roadway. This could make for a dangerous situation away from the city, where the streetlights aren't around to light up the way.
The easiest way to fix a problem like this is to re-aim your factory headlights, although, some vehicles are so high that the factory lights are ineffective, or have become too far from the pavement by law. Creative truck owners have overcome this problem by mounting auxiliary headlights, or in some cases, mounted headlights in the bumpers and integrated them into the overall truck's design.
Ride and Suspension
Many first-time lifted truck owners don't realize the ride penalty in going high. Not all kits are created equal, and a rough-riding rig can add to fatigue on long trips, make controlling the vehicle exhausting, and put wear on the truck itself. Generic suspension tuning and low-quality shocks can lead to driveability issues, such as vibrations, axle hop, and loss of suspension damping, which would lead to a more serious problem. While on the subject of suspension lifts, torsion bar twisting is an inexpensive method many people use to lift their truck, which may be OK for leveling, but it is not a true lift because it merely adjusts the level at which the truck sits in its suspension travel. Therefore, tires that rub at stock height will still rub with a torsion twist somewhere in the suspension travel. Also, the higher you go with a twist, the less down travel you will have, causing quirky handling, such as skipping across the road imperfections, rather that soaking them up. On 4x4 vehicles, this also causes an issue because you could over-extend a CV axle joint on a truck that has excessive compression, but limited droop.
Spring and shock technology has come a long way in recent years. Reservoir shocks and coilover shocks once reserved for high-end race trucks are now within reach of many truck builders. These damping units are easily tuned, adjustable for ride height (coilovers), and are readily available from many high-end shock suppliers, such as Bilstein, Fox, King, and Sway-A-Way. Custom leaf springs, tuned to your vehicle and your needs, can easily be purchased from Atlas, Deaver, or National, just to name a few quality companies. Traction bars that locate the axle to the frame to reduce unwanted movement and axle hop are another way to tame the wildness in your suspension.
After a lift, many people forget to take into account the speedometer error that has been introduced to the truck because of a change in tire size. Bigger tires cause the speedometer and odometer to read slower than the vehicle's actual speed, altering transmission shift points, traction control, and ABS functionality. While some manufacturers have a built-in buffer to compensate for some change in the tire's overall diameter, it only covers changes within 1 or 2 inches of stock.
On older trucks, change the speedo gear at the end of the speedometer cable. Located either in the transmission or transfer case, this gear is simple for any mechanically inclined truck lover to replace. Newer vehicles sporting the latest in electronics often have a Vehicle Speed Sensor (VSS) which uses electronic sensors to tell the truck's computer how fast the truck is moving. Thanks to companies such as JET and Superlift, speedometer calibration on a vehicle equipped with a VSS is as easy as programming a new plug-in, or splice-in module.
The whole purpose of lifting a truck is to increase the size of tire that can be installed, especially since increasing tire size is the only true way of gaining ground clearance at the axle. But, even lifting might require some fender trimming if you go with a monster tire. When choosing tire size, you must take into account the suspension settling after the initial installation. Remember, a tire that fit on the day of the lift may end up rubbing down the line. Bigger tires mean lower manufacturing tolerances and will be harder to balance. Also, the higher up in size you go, it may be harder to find a radial tire in the size you need.
Large tires - let's say, more than 38 inches - should be closely checked and rebalanced after 500 miles, because the rotating mass has a tendency to actually rotate on the wheel, altering the balance and causing vibration. A large all-terrain will have better street manners than an aggressive mud-terrain, and a radial tire will be superior to a bias-ply tire. It is also important that the tire you are installing on your truck be DOT-approved for the street, and load-rated for the weight of your vehicle, fully loaded.
The higher up you are, the greater the view of the road ahead, right? Well, yes, but to a point. There is a point of diminishing returns where the higher you go, the less visibility you have. Monster street truck drivers are at the distinct disadvantage in close quarters when maneuvering, such as in stop-and-go driving, city traffic, and even parking. It is nearly impossible for a driver of a towering tow vehicle to see the tiny cars in front of him, measly pedestrians, or even unpredictable bike riders. Factory mirrors are inadequate at such high heights, and lane changes are usually accomplished with the help of small miracles.
There is no perfect solution to visibility issues, but we advocate the use of factory or aftermarket reverse-sensing systems, and convex mirrors as a minimum. We have started seeing innovative truck owners use camera systems, not only for reverse procedures, but mounted on the front bumper and in the front wheelwells to cover blind spots on all sides, and the images appear on a monitor in the cab. The best tool for driving a too-tall truck is caution.
Not just any wheels can be used with big tires - no matter how cool they look. Just like with tires, wheels are also rated to carry a load, and most ratings max out at a specific tire size. Porous cast wheels, and even some steel wheels weigh more, and carry less of a rating than those high-end forged wheels.
Rated forged wheels are lightweight and precision-built very strong. Forged rims balance easily, and run truer than cast wheels or steel wheels. These wheels are also more durable when holding big-time rubber, and less likely to crack or have a structural failure.
We have tried to cover the entire gamut of extreme lifting problems and solutions in a general way that will be useful to the largest number of readers. While we may not have included every situation you may encounter in lifting your throne on wheels, hopefully this article has helped you to answer questions and give you direction in how high to go in your quest to have the ultimate daily driver. As you can see, the general theme of this article is the bigger you go, the more things need to be addressed. Only you can determine how comfortable you are living with the eccentricities of having a super-cool, super-clean big rig.
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