Lift System Basics
Lift System Basics
The decisions you make regarding suspension alterations are important ones. Closely evaluate what you have to work with and think about what you are trying to accomplish. Most of us own trucks or SUVs that serve multiple roles; our vehicle is primarily a daily-driver, with its other duties being a weekend project "work mule" - with possibly a little towing thrown in - and occasionally some off-roading. In this multi-use situation, the goal is to find the proper balance between on-road drive ability (see definition below) and off-road suspension flexibility and control. If you have the luxury of owning a dedicated off-road vehicle, some of its higher speed handling traits can be sacrificed to maximize suspension articulation. Also realize that suspension is only one leg of the performance triad, you must also address your vehicle's tires and drive train... the key is to get these three vehicle systems working together to provide the best possible traction at all times. Hey... if it were easy and cheap, everyone would be doing it correctly!
What suspension system will work best for you? It boils down to these four basic factors:
- vehicle type and stock suspension specifications
- what the vehicle will be used for
- desired tire size
- your budget
Because of all of the variables, odds are that a one type fits all lift kit is not going to get the job done satisfactorily. National Tire and Wheel allows you to build a suspension system for your specific budget and performance needs. No one offers more lift methods and options than National Tire and Wheel. If you still have questions contact us direct to discuss your situation in detail.
Vehicle drive ability is defined as: The sum of a vehicle's driving traits and mannerisms. Over the years, the vehicle manufacturers (Ford, GM, Dodge, Toyota, etc.) have paid more and more attention to drive ability, especially in the area of ride quality. A properly modified, moderately lifted vehicle generally rides and steers as well as a stock vehicle. In fact, it is not unusual to actually noticeably improve overall drive ability, depending on your choice of suspension, shocks and tires. Again, it is a matter of what vehicle you start with and your aftermarket equipment choices. Here are a few rules of thumb to keep in mind:
- Coil spring lift systems normally maintain a factory-like ride quality.
- Lifted leaf spring equipped vehicles generally ride factory-like or slightly firmer than stock. As spring arch increases so does firmness.
- On most vehicles equipped with Independent Front Suspension, ride quality does not noticeably change since the factory torsion bars or coil over shocks are not replaced.
- Properly valved shocks, or multiple shocks per wheel, help cure a spongy ride, but they will not provide lift.
- Tire type and their operating air pressure - Most people keep their tires at operating pressures higher than what is needed for their vehicle's weight. For example: a full-size SUV requires more pressure than a Jeep CJ, yet they can run the same basic tire. Over-inflation degrades ride quality, and induces uneven tire wear. Research what pressure is right for your vehicle's weight via your tire dealer or the tire manufacturer's website.
- Lift blocks are generally the most popular rear lift method since they afford the best ride quality and are the least expensive. However, spring / axle wrap-up can be an issue with some vehicles. National Tire and Wheel offers many different anti-wrap traction bar products: the economical top-mounted bars, or the ladder type bars.
- Add-a-leafs can be used with or without lift blocks, and are recommended to strengthen weak factory springs and/or when the vehicle is used for hauling or towing. Top-mounted factory overload springs can be retained when using add-a-leafs.
- Full replacement rear springs are the way to go if the factory springs are overly fatigued or damaged. Attaining lift with new springs, as opposed to blocks, reduces spring / axle wrap-up. Generally, replacement rear springs' ride quality and spring rate is comparable to a factory heavy-duty spring. Top-mounted factory overloads are not compatible with rear lift springs generally.
- Net lift height varies slightly depending on which factory suspension package the vehicle is equipped with and its condition.
- The presence of additional weight, such as a winch, heavy-duty bumpers, storage boxes, extra fuel capacity, etc., reduces lift height.
- On vehicles equipped with Independent Front Suspension, the use of exceptionally wide tires / wheels exerts extra leverage on the vehicle's springs and reduces tire-to-fender clearance when turning. This leverage results in a slight amount of ride height loss. With torsion bar-equipped vehicles, the available torsion bar adjustment may not be adequate to offset this leverage, and new heavier rated bars may be required. For other suspension types (TTB, coilover), National Tire & Wheel offers products that will restore this lost height.
How will lifting my truck affect my drive shafts?
Drive line correction methods are incorporated into virtually all suspension systems. For example, most rear lift blocks are either tapered or flat, depending on application, to address drive shaft angle. Most replacement springs have a tapered degree shim attached, where applicable, to accomplish the same thing. Rolling the pinion upward also restores some shaft spline contact. Sometimes the blocks' pins/holes are offset to address shaft length issues.
More on drive shaft length: Generally, shafts must not be lengthened unless the suspension lift height is over 6 inches. Unless specifically noted in the installation notes, there is normally no need for replacement or lengthened drive shafts when the lift components are installed properly.
How complicated is installing a lift system?
Installation time and complexity varies greatly from application to application. Generally speaking, lifting a vehicle with Independent Front Suspension (IFS) is more involved than lifting a vehicle with solid axles front and rear.
How will a lift system affect my ride quality and handling?
There are more variables here than there are Clinton jokes. So many things influence the above...
The bottom line is that drive ability traits will change, but the degree of change varies. On vehicle stability, the general rule is: "the taller a vehicle, the easier it will roll over," but conversely, it is not unusual for moderately lifted vehicles with moderately taller and wider tires / wheels to be as stable or more stable than their stock counterparts. The key is to take time to learn these new capabilities and limitations, and to drive responsibly.
Is a front-end alignment required after installing a lift?
The need for front-end realignment following the installation of a lift varies according to make, model and suspension design. Even if an alignment is not required, it should be part of your regular maintenance regimen to ensure proper handling and tire wear.
For more information, see the installation notes for your specific lift system.
Why is the listed rear lift height less than the front?
The vast majority of non-modified pickups set about two inches high in the rear when empty. This is so the truck's rear end will not be excessively low when the truck is loaded. With most people that lift their rigs, towing and load carrying is not a priority - lifted performance, tire clearance, and vehicle "look" are the primary issues. A more level stance is desired, and extra room is needed on the front, so the tires can clear the fenders when turning. Also, a more even front-to-rear attitude improves an unladen vehicle's weight distribution which generally improves its handling when not carrying a load. Note that on most applications you have the option of altering rear lift height and /or method.
How will a lift system affect my new vehicle's warranty?
The Specialty Equipment Market Association, a trade group that works on behalf of aftermarket performance manufacturers, has a complete list of your rights regarding warranties and aftermarket equipment. Generally speaking, the dealer can only refuse warranty work if they can prove that the aftermarket part has caused the problem.
Click here to see SEMA's answer to this very frequently asked question.
Does my state have any restrictions on lift height?
Contact your state's Department of Motor Vehicles.
Not all states limit lift height, but those that do use different methods and measuring points (bumper height, frame height, headlight height, etc.). National Tire & Wheel will not be held responsible for your states laws and regulations.
Why can't I find a taller lift for my vehicle?
Suspension lift designers must take what the factory design gives them. For example: an older leaf spring General Motors pickup can be lifted up to 12", and depending on its running gear, feasibly run the largest tires. But, because of its factory design, the newer versions (1988 and newer) of the same General Motors truck is not receptive to being lifted in excess of 6 to 7 inches. Its steering linkage and front IFS axle is considerably lighter-duty than its solid axle predecessor, and does not hold up well when exposed to tires in excess of 36 inches tall.
Generally speaking, if we do not offer a system as tall as you think you need, you probably shouldn't go there.
Will I need to change shocks after installing a body lift?
Since a body lift does not change the distance between the vehicle frame and the axles, new shocks are not a "gotta do" when installing a body lift. Be aware though, that most standard factory shocks are cheesy at best, and last about as long as a Mike Tyson pay-per-view fight. The same applies for factory steering stabilizers. Check the condition of the mounting bushings, and the cylinders for signs of fluid loss.