Suspension
Independent Front Suspension
The front suspension consists of torsion bars, upper and lower control arms, and shock absorbers. The suspension can be raised 1.5 to 2.5 inches by increasing the torsion bar preload. Too much preload will reduce down travel and drastically alter the suspension, steering and wheel alignment, which causes rapid and uneven tire wear and handling problems. Aftermarket upper control arms provide better suspension geometry and alignment for trucks with more than 2.5 inches of torsion bar lift. Trail Master’s 4 inch suspension lift utilizes dropdown brackets which doesn’t require “cranked” torsion bars to achieve lift, but can be combined with an upper-control-arm lift for more than 4 inches of lift.
Upper Control Arms
Superlift upper control arms (UCA) restore proper ball joint angle, camber angle and allow sufficient extension travel with cranked torsion bars. Amount of lift is dependant on how much the torsion bars are cranked.
NOTE: The bolts securing the upper link spindle to the frame often come loose.
Use threadlock and torque to the maximum 108 ft lb.
Torsion Bars
Sway-A-Way torsion bars are manufactured from aircraft alloy steel and have a 20% to 30% higher spring rate over OE torsion bars. They improve vehicle handling, eliminate hard bottoming when off roading or towing heavy loads, and provide a consistent spring rate for better vehicle control.
Re-indexing torsion bars:
1. Put the truck on jacks stands.
2. Loosen the tension on the torsion bars by loosening the adjuster arm bolt on both sides.
3. Mark the original location of the torsion to anchor arms on the lower control arms so that you have a reference point.
4. Loosen the 3 bolts on the anchor arm.
5. Pull the anchor backward on the torsion bar.
6. Turn the outside of the anchor toward the ground a few splines. NOT TOO MUCH because you don't want to bottom out on the bumpstops afterwards.
7. Make sure the other side is turned the same amount of splines.
8. Install is the reverse of the removal procedure.
9. Double check the upper a-arms so they're not bottomed out on the bump stops. If they are, the anchors will need reindexing again, backing them off a few splines.
10. Double-check the height of the truck on each side so that it's leveled. Measure from top of the tire to the bottom of the fender and make sure the measurements are same.
Ultra Low Profile Bumpstops
These bumpstops are necessary to acheive more lift. They provide more clearance between the frame and upper control arm to crank the torsions up a little higher.
Trail Master 4" Suspension Lift
This lift utilizes dropdown brackets for the front differential, spindles, torsion bar cross member and lower control arms for a true 4" suspension lift.
Hardbodys with the R180A front differential require an additional kit (part #8040) to relocate the front differential. Without this kit, the differential will bind on the frame and lead to driveline failure.
This lift require rims with a back spacing of 3.75 inches or less and the tierod assemblies require cutting to fit.
The Trail Master lift is listed for 86.5 to 92 models only. To get this lift to work for the 93, I swapped the outer tierod ends with a 90 model. The outer tierod ends are left-hand-thread, so make sure you have your outers on the outers and the inners on the inners.
Trail Master lift Instructions
Rear Suspension
The rear suspension consists of leaf springs, shackles and shocks. The Trail Master lift included 3" lift blocks to lift the rear. Other methods are shackles, add-a-leaf and custom leaf packs.
Blocks or Add-A-Leaf install
Add-a-leaf
A common way to lift the rear is with an add-a-leaf. An add-a-leaf is a single leaf spring designed to re-arch the primary OE leaf springs. The add-a-leaf handles axlewrap better than blocks. Axlewrap happens when the axle rotates during acceleration, affecting performance and driveability. Another way to cure axlewrap is adding traction bars.
Shackles
Lift shackles provide more lift without re-arching the spring pack keeping the soft, stock ride.
Revolver Shackles provide moderate lift and more articulation of the rear suspension.
Traction Bars
Traction bars will remove any and all axlewrap the vehicle may have. They improve traction and acceleration by maintaining tire contact where it belongs. Vehicles with smaller tires won't experience much axlewrap as those with larger tires.
Suspension Bushings
Polyurethane bushings last a lot longer than rubber, but a few benefits of rubber is a softer ride and it's not as NOISY.
Shocks
The Trail Master lift included their Speed Smart Valving (SSV) shocks, but they are no comparison to the Rancho 9000 adjustable shocks. The 9000s provode 5 settings to adjust ride quality for off road and highway driving.
Links
Automotive Customizers
Energy Suspension
Rancho
Superlift Suspensions
Sway-A-Way
Trail Master
