[DevinSixtySeven]

Stock Suspension
In front, the Tundra uses a double wishbone independent suspension with a coilover fitted roughly halfway down the lower control arm. The rear uses a leaf spring over the rear axle, with the frame hanging from the shackle at the aft end of the spring as opposed to the weight sitting on the shackle. The front of an access or regular cab tundra is roughly 2" lower than the rear to provide load leveling--when the proper working load (half the max rated payload) is placed over the rear axle, the truck should ride level, at least that's the idea. If anyone knows the weight over the rear axle at which the stock truck sits level, please PM me.

A shock absorber consists of two components, a spring and a damper ("shock"). The spring is what actually flexes over a bump, while the valving in the damper is set to prevent the spring from bouncing. In front, the damper ("shock") mounts in the center of the coil spring, hence the term "coilover". In the rear, the leaf pack is the spring, with one shock mounted in front and one to the rear of the axle to help control axle wrap.

There are two main types of lift for IFS, each creates a lift in a different way and with different tradeoffs. Coilover lifts change the ride height by translating the position of the coil on the damper. Drop brackets are unique to independent suspension systems and provide a spacer to move the lower control arms, differential, spindles, coilovers, and steering components lower than their stock position on the frame. For the rear of the truck, the two general methods of lifting are changes or additions to the leaf spring pack, and blocks--shackle lifts cannot be applied without flipping the shackle, but this also means a longer shackle can be used to lower the rear of the truck (drop shackles are sold by SOS Performance and others). Body lifts change the distance between the frame and the body of the truck (cab and bed), and provide clearance between tires and body but do not affect suspension or drivetrain components.

Coilover Lifts (and Spacers)
A coilover lift changes the static ride height by translating the position of the coil. A coilover drop kit (again, see SOS Performance) does the same thing, but moves the spring in the opposite direction. Below, the "XXXX"s are the shock body, "SSSS" is spring, and the "===="s are the shock shaft. The "0"s are the mounting eyes. The spring is shown next to the shock for position, the "-"s next to the spring are just spacers so everything looks correct. The "C" is the spring seat on the coilover.

This is full compression:
0XCXXXX0
---SSSSS-

This is full extension:
0XCXXXX======0
---SSSSSSSSSSS-

This is normal ride height:
0XCXXXX===0
---SSSSSSSS-

The spring will always be compressed the same amount when the static weight of the truck is on the spring (ie nothing is moving, truck/suspension is at rest), regardless of the ride height, within reason--this doesn't include ridiculously impossible lower control arm angles. When the "lift height" is changed, all that's changing is the compression/extension ratio on the damper...the piston is either moving in or out, but the spring is compressed the same amount. In other words, it is not a change in "preload"...there is no such thing as "preload" as the term is commonly used to describe spring seat adjustment. If the spring were actually "preloaded", it would not flex at all (!) on the truck until the static or dynamic load from the truck's weight increased to the point where it was equivalent to the force exerted by the "preloaded" spring.

Normal:
0XCXXXX===0
---SSSSSSSS-

Higher Ride Height:
0XXXCXX=====0
------SSSSSSSS-

So the more the ride height is lifted with a coilover, the less extension the shock has remaining, which will affect ride quality and potentially shock life. In addition, as the ride height increases, the angle on the lower control arm increases, which results in a stiffer ride as the tire must move laterally in order for the suspension to compress. The increase in angle also decreases the volume within the CV boots on the front driveshafts, raising the internal pressure and often forcing CV grease out the ends of the boot, resulting in the spinning driveshaft flinging grease at surrounding components.

The additional angle (above about 2") causes the CV joint to rub on the inside of the stock inner CV boot and eventually tear, and the CV joint itself is more likely to break as the running angle increases. Larger Porsche 930-style inner CV boots are available to address the rubbing issue (see elsewhere in this FAQ). The front drivetrain can be disengaged using a manual hub kit, enabling the suspension to be run day-to-day at a higher angle, but this does not solve the problem offroad. Always bear in mind that a CV joint is strongest when it is not flexed.

When adjusting the ride height, the ratio of coilover adjustment to wheel height adjustment is roughly 1:1.6, also when the truck is set on its own weight post-adjustment, the steep lower control arm angle will be held by the tires--remember as the LCA angle increase, the tires need to move laterally for the suspension to compress. Measuring lift immediately post-install will result in a false number; scrubbing the wheels side to side (ie turning the steering wheel in place) will help but the best method is simply to roll the truck backwards, then forwards since the vehicle's alignment will help "track" the wheels to their proper location. Normal toe will encourage the suspension to rise slightly when moving forward, and settle slightly in reverse--this is also why people with suspension lifts, oversize tires and stock mud flaps & wheel wells may notice rubbing in reverse but not forward.

Note this will not work if the toe has been significantly changed by the lift, ie going from stock to 4" lift, as the misaligment will cause the front of the truck to rise and settle significantly--in this case, scrubbing the tires on a loose surface (or a couple sheets of cardboard) will be the best method to estimate lift height. If possible, measure the lift height on the alignment rack, while the suspension is floating, and readjust if necessary, followed by realignment as the camber, caster and toe angles will have changed as a result of the new control arm angles.

The ONLY real difference between one coilover lift method/brand/type and another is whether the shaft remains stock length or is extended, either to take advantage of the remaining travel in the upper ball joint, or to be used in conjunction with a uniball upper control arm (note this does not mean Bilstein = SAW = Fabtech = Donahoe = etc, only that their lift methods may be of the same type...their springs, dampers, build quality, materials etc may be completely different). The length of the coilover can be extended using a spacer on top of the coilover assembly, which must either be thin enough not to compromise the stock upper ball joint, or a uniball joint with a greater range of travel must be installed as well. Spacers which install within the coilover assembly do not carry this risk, but because they bias the travel ratio far towards compression the shocks are prone to extending hard and may damage the shock over time. Limit straps mitigate the hard extension, are inexpensive and easy to install. An adjustable coilover is really no different or better than a non-adjustable spacer as far as ride height is concerned. The only difference between kits is whether or not they allow additional travel, and if so, how much--enough to require a uniball upper ball joint, or not.

Spacer kits should never be combined with aftermarket coilover kits. Most aftermarket coilover kits already account either for the additional travel available in the stock upper ball joint or are intentionally extended to leverage the additional angle available with a uniball upper ball joint. As a simple example, do not try to install an EZ-Lift puck on top of your Bilstein 5100 coilover kit, they were never meant to be installed together and the result will likely damage your upper ball joint--see this example of a damaged joint on Camburg's website.

Drop Bracket aka Cradle Lift
The point of a drop bracket is to increase lift height while maintaining near-stock suspension angles, allowing for more height than a spring seat adjustment alone (coilover or spacer kits). The main crossmember is cut and a subframe is bolted underneath. This subframe holds the lower control arms, steering rack and front differential several inches (usually 3-4") below the frame. RCD and Tuff Country manufacture this style lift for the Tundra. These kits are often combined with suspension adjustments to provide as much as 6" of ride height over stock. Custom drop brackets have been built as well and may be found by searching the forums and photo gallery.

There are two types of designs for drop bracket kits. Since the lower control arms etc. are relocated, the spindles must be lengthened as well. The older style of kit uses a spacer on top of the spindle, which has broken on several trucks. The newer style uses a replacement spindle with length matching the drop bracket. Both RCD and Tuff Country offer a kit with a replacement spindle.

Drop bracket kits offer no offroad capability over stock, they are only a means to fit a larger tire and gain height. They do not offer more articulation, center of gravity is increased more than a suspension/body lift combination, they do not contribute to the strength of the drivetrain, and height is increased without any increase in width, so sidehill stability is compromised compared to stock. Once a drop bracket is installed the truck cannot be returned to stock without a great deal of effort. Ground clearance under the differentials is only changed by an increase in tire size since the kit lowers the mounting point of the steering rack and lower control arms. While these kits are hardly the best solution offroad, they are certainly strong enough and the truck will remain perfectly capable of negotiating fire roads and moderately difficult trails, where sidehills are not steep and the need for articulation is no greater than stock. These kits generally allow a 35"x12.5" tire to be fitted to the truck, with the addition of a body lift a 37"x12.5" tire may fit in some circumstances.

Body Lifts
A body lift, like a drop bracket, is a brute force method for relocating the rear corner of the front wheel well. Body lifts use a polyurethane, plastic or metal puck to increase the space between the cab and the frame, generally 1" to 3" thick. Brackets and/or extensions are also required for the steering linkage and radiator mount. Like a drop bracket, a body lift does not increase offroad capability, but unlike a drop bracket a body lift allows fitment of a larger tire without irreversible modification to the vehicle. A body lift also does not raise the center of gravity as much as a drop bracket, comparing two trucks with equal tire size and equal measurements from the ground to the body pinch weld. Neoprene fabric can be used to cover the gap between body and frame, or search for a kit called "Lift Lips". It is possible to mount 35"x12.5" tires using a 3" body lift and a 2.5" suspension lift, this is a very functional setup offroad tho the tires may rub during compression turns to full lock. FYI the six stock bolts in the bed require a T-55 Torx bit.

Long Travel
Stock travel is 6". Long travel kits from Total Chaos and Camburg normally achieve 13" of travel, and with some modification can reach 15" with functional 4WD. This is achieved using a uniball to replace the stock upper ball joint, allowing more travel, and by lengthening the arms 3.5" each side. For a wealth of information on long travel tech, use and abuse, visit SoCal Tundras. The wheel mounting surface (wms) dimension for these kits is 74" (stock rear is 66", front is 67"). This might sound wide, but with a reasonable wheel and tire combination the total width can be well under 85", potentially as narrow as 79" depending on section width, rim width and backspacing. Note also that for wide and tall tires, track width may be as wide as 89", for example 17x10 rims on 4.5" backspacing with a 37" tire and 14" section width.

Both the Chaos and Camburg kits are race-proven in the Southwest and on the Baja peninsula. Both kits are very high quality, and staff at both manufacturers are incredibly helpful. Either kit will work for 2WD and 4WD trucks, and builds with these kits should be at home in the open desert and on trails through the woods, if tires and rims are kept at reasonable widths. Tho expensive, these kits are excellent additions to an offroad-oriented build for a vehicle which will remain IFS.

Solid Axle Swaps
Please see Teddnet.com for information on Tundra solid axle swaps, and search the forums here for information on the handful of 1st-gen Tundras running solid front axles.

A solid front axle is the least expensive route to the most durability and flexibility of the front suspension and drivetrain. Bear in mind "least expensive" is in comparison to bombproof 4WD independent front suspension builds, which can run similar in cost just for LT arms and 930 axles and cannot improve the strength of the differential without custom work. Swapping in a new front axle will also allow for narrower track width options than long travel IFS, and the wheelbase can be stretched to improve the front/rear weight distribution as well as clear the frame and firewall with a much larger tire.