Main Menu Vehicle Trails Mechanicals TJ/LJ Mods JK Mods Gallery
TJ and LJ Wheel Alignment

Wheel Alignment

The lift does effect the toe. It causes Toe-in. As you drop the suspension away from the frame, the tie rod and drag link pull the tires in (toe in). Take a look at your front end, you will notice that the tie rod is connected to one tire, and the drag link to the other, they from kind of a Y. Now the connection points at the steering knuckles are going to stay at the same height, but the physical distance between them is going to get shorter while the distance between them and the last point (pitman arm) is going to get larger. This larger is just a physical measurement, the rod lengths never changed. The pit man arm moved over to compensate, that is where the additional length came from. Basically you are pulling on one end of the Y, the other 2 ends have to get closer to compensate for this.

Lifts create 2 main problems with the steering that can be addressed by steering adjustments. I'm not going to address the others (caster and camber). There are 2 adjustments one on the drag link (steering wheel) and one on the tie-rod (toe-in/out). We can adjust the drag link and make it longer thus centering the steering wheel, this will push the pitman arm back into its normal position, but doesn't move the tires. While this will be adequate to allow you to drive, it won't completely get ride of the bump steer. The other problem is that we will still have toe-in. For this we will need to adjust the tie-rod out also to length the distance between the tires again. If you were to drive around with out getting the toe-in adjusted you are basically driving and pulling your tires sideways along the road surface. Concrete and asphalt work very well as sandpaper. Example would be my friend who didn't get an alignment like I told him to and he scrubbed off half of his tread in 3,000 miles. Didn't make his wife very happy. The only problem left that I didn't mention is the higher the lift, the more extreme the angles are going to get and eventually they will not work with each other and you will not be able to make any adjustments to compensate. This is when the drop pitman arm comes in.

What a drop pitman arm does/ tries to do is lower the angle created by the lift. As you saw above we pulled on the one side of the Y, but if we put the drop pitman arm in, we lower the connection point reducing the angle, the distance of pull so we creating a more stable ride. Even with the drop pitman arm in you will need to get it aligned after doing a lift. Generally on 4" of lift manufacturers have been including a drop pitman arm. In the past this dropped arm increased the amount of torque on the steering box, since the force was now at a greater angle. With the new mounting on the TJ's and especially the new cast iron steering box for the 2003's I don't believe this is an issue any longer. If anyone has seen damage caused by this please let me know, so I can amend any statements.

DESCRIPTION - Wheel alignment involves the correct positioning of the wheels in relation to the vehicle. The positioning is accomplished through suspension and steering linkage adjustments. An alignment is considered essential for efficient steering, good directional stability and to minimize tire wear. The most important measurements of an alignment are caster, camber and toe position (Fig. 1).

CAUTION: Never attempt to modify suspension or steering components by heating or bending.

OPERATION

CASTER is the forward or rearward tilt of the steering knuckle from vertical. Tilting the top of the knuckle rearward provides positive caster. Tilting the top of the knuckle forward provides negative caster.  Caster is a directional stability angle. This angle enables the front wheels to return to a straight ahead position after turns (Fig. 1)

CAMBER is the inward or outward tilt of the wheel relative to the center of the vehicle. Tilting the top of the wheel inward provides negative camber.  Tilting the top of the wheel outward provides positive camber. Incorrect camber will cause wear on the inside or outside edge of the tire. The angle is not adjustable, damaged component(s) must be replaced to correct the camber angle (Fig. 1)

WHEEL TOE POSITION is the difference between the leading inside edges and trailing inside edges of the front tires. Incorrect wheel toe position is the most common cause of unstable steering and uneven tire wear. The wheel toe position is the final front wheel alignment adjustment (Fig. 1)

Wheel Alignment Measurements

STEERING AXIS INCLINATION ANGLE is measured in degrees and is the angle that the steering knuckles are tilted. The inclination angle has a fixed relationship with the camber angle. It will not change except when a spindle or ball stud is damaged or bent. The angle is not adjustable, damaged component(s) must be replaced to correct the steering axis inclination angle (Fig. 1)

THRUST ANGLE is the angle of the rear axle relative to the centerline of the vehicle.  Incorrect thrust angle can cause off-center steering and excessive tire wear. This angle is not adjustable, damaged component(s) must be replaced to correct the thrust angle (Fig. 1)

STANDARD PROCEDURE - CAMBER
Before each alignment reading the vehicle should be jounced (rear first, then front). Grasp each bumper at the center and jounce the vehicle up and down three times. Always release the bumper in the down position.  The wheel camber angle is preset. This angle is not adjustable and cannot be altered.

STANDARD PROCEDURE - CASTER
Before each alignment reading the vehicle should be jounced (rear first, then front). Grasp each bumper at the center and jounce the vehicle up and down three times. Always release the bumper in the down position.  Check the caster of the front axle for correct angle.  Be sure the axle is not bent or twisted. Road test the vehicle and observe the steering wheel return-to-center position. Low caster will cause poor steering wheel return ability.  During the road test, turn the vehicle to both the left and right. If the steering wheel returns to the center position unassisted, the caster angle is correct.  However, if steering wheel does not return toward the center position unassisted, a low caster angle is probable.  Caster can be adjusted by installing cam bolts and rotating the cams on the lower suspension arm (Fig. 2).

NOTE:
Changing caster angle will also change the front propeller shaft angle. The propeller shaft angle has priority over caster.

STANDARD PROCEDURE - TOE POSITION
Before each alignment reading the vehicle should be jounced (rear first, then front). Grasp each bumper at the center and jounce the vehicle up and down three times. Always release the bumper in the down position.

NOTE: The wheel toe position adjustment is the final adjustment. This adjustment must be performed with the engine running, if the vehicle is equipped with power steering.

(1) Start the engine and turn wheels both ways before straightening the steering wheel. Center and secure the steering wheel.
(2) Loosen the adjustment sleeve clamp bolts (Fig. 3).
(3) Adjust the right wheel toe position with the drag link (Fig. 4). Turn the sleeve until the right wheel is at the correct positive TOE-IN position.  Position the clamp bolts as shown (Fig. 3) and tighten to 49 Nm (36 ft. lbs.).  Make sure the toe setting does not change during clamp tightening.
(4) Adjust the left wheel toe position with the tie rod. Turn the sleeve until the left wheel is at the same TOE-IN position as the right wheel. Position the clamp bolts as shown (Fig. 3) and tighten to 27 Nm (20 ft. lbs.). Make sure the toe setting does not change during clamp tightening.
(5) Verify the right toe specifications and turn off the engine.

Cam Adjuster Drag link and tire rod clamp steering linkage

ALIGNMENT SPECIFICATIONS

NOTE: Alignment specifications are in degrees.

DESCRIPTION

FRONT SPECIFICATION

PREFERRED

CASTER
+ 7.0

CAMBER
(Fixed Angle)
- 0.25

TOTAL TOE-IN
+ 0.15
(each front wheel)

RANGE

1.0

0.63

0.06

MAX RT/LT DIFFERENCE

0.65

1.0

.06

REAR SPECIFICATION
PREFERRED

N/A

REAR CAMBER
-0.25

TOTAL TOE-IN
+0.25

RANGE

N/A

0 to -.50

0 to .5

THRUST ANGLE 0 0.25

This page last updated: 16-Apr-2008

Content and Design © 2002-present WanderingTrail,  Ron Seegert
Common Sense and Safety should always be observed when working on your vehicle or doing modifications. Jackstands, wheel blocks, disconnecting the battery are a few of the basic safety precautions that should be used and may not be mentioned in the write ups on this site. You are responsible for your own installation, these write ups are a helpful guideline and should not be taken as an official installation instruction. My write up may be different from the kits currently out there, so alwasy double check the manufacturers installation instructions when installing anything. I try to keep the site up to date with changes that have occured as I discover them, but may not have the latest unless someone lets me know. If you feel that an install is above your capabilities after reading my write ups, I recommend getting together with a club and getting some help. Only a few times have I needed to employe some actual help from a shop to get something done. Usually welding or A/C work.
All trademarked names & logos are property of their respective owners
This site is in no way associated with Daimler-Chrysler
Jeep is a registered trademark of Daimler-Chrysler