Wheel alignment check

The angle relationships between the front wheel/front suspension installation parts and the ground are described in this section.
Ensure effective steering and good directional stability and maintain adequate wheel alignment to prevent abnormal tire wear.
The most important elements in the wheel alignment are wheel toe-in, wheel camber, and axle caster.

1. Camber

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a. Camber

Standard value

b. 90°

The camber is facing toward the inside or outside of the front wheel and tilted in up and down directions.
If the wheel is tilted up and outward, the camber is positive (+). If the wheel is tilted down and inward, the camber is negative (-).
The tilt angle measured against the vertical is the camber angle. If the camber angle is extreme or uneven between wheels, improper steering and excessive tire wear may result.
While positive camber causes wear on the outer part of the tire, negative camber causes wear on the inner part of the tire.

2. Caster

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a. Caster

Standard value

b. 90°

The caster is tilted in up and down directions according to whether the wheel axis is forward or backward.
The backward tilting is positive (+) and forward tilting is negative (-) (when the vehicle is viewed from the side).
In case of short and long arm type suspension, the caster angle can be measured only by special equipment. However, when viewed straight from the top of the upper link toward the ground, the ball joint is not aligned (overall) when the caster angle is not 0°. If the angle is positive, the lower ball joint may be at a position slightly forward of the upper ball joint center line.

3. Toe-in

Toe-in is the measurement of front wheel rotation.
Actual toe-in amount is normally represented by angle rate. Toe-in is measured from the center of the tire tread or inside of the tire.
The purpose of toe-in is to ensure parallel rolling of the front wheels and to offset any vibration of the wheel support system caused by forward rolling of the vehicle.
Wrong toe-in may lead to excessive toe-in or unstable steering. Toe-in is the last alignment set in the wheel alignment work.

1. Wheel alignment measurement conditions

Measure with the vehicle unloaded (without passengers or a load).
Check the inspected areas again before adjusting the wheel alignment.

2. Inspection before measuring wheel alignment

1) Inspect for the following.

3. Trim height measurement

1) Measure the buffer clearance and trim height.

2WD (Except high ride suspension specifications)

Buffer clearance (Reference value)	25.9 mm { 1.02 in }
Trim height (Reference value)	119 mm { 4.7 in }

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a. Buffer clearance

b. Trim height

2WD (High ride suspension specifications), 4WD

Buffer clearance (Reference value)	26 mm { 1.02 in }
Trim height (Reference value)	140 mm { 5.5 in }

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a. Buffer clearance

b. Trim height

4. Adjustment of the trim height

1) Loosen the cam bolt lock nut.

2) Rotate the cam bolt and adjust the buffer clearance and trim height.

2WD (Except high ride suspension specifications)

Buffer clearance (Reference value)	25.9 mm { 1.02 in }
Trim height (Reference value)	119 mm { 4.7 in }

Legend

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a. Buffer clearance

b. Trim height

2WD (High ride suspension specifications), 4WD

Buffer clearance (Reference value)	26 mm { 1.02 in }
Trim height (Reference value)	140 mm { 5.5 in }

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a. Buffer clearance

b. Trim height

3) After adjusting the buffer clearance and trim height, tighten the lock nut to secure the lower link.

Tightening torque: 186 N・m { 19.0 kgf・m / 137 lb・ft }

5. Caster and camber adjustment

1) Park the vehicle on a level surface.

2) Inspect the wheel alignment using an alignment device.

3) Loosen the lower link cam bolt nut as necessary.

4) Adjust the caster and camber.

An adjust cam is fitted to either front or back end of the front suspension lower link. This allows for simultaneous adjustment of camber and caster angles.

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The following illustration describes the camber and caster adjustment procedure.

As an adjustment example, measurement values from the following table are used here.

Measured value (Example: 2WD (Except high ride suspension specifications))

Camber angle	1°10'
Caster angle	3°10'

Standard value (2WD (Except high ride suspension specifications))

Measurement items	Standard value		Remarks
Camber angle	0°±30'		Equally in right and left sides in 30' range
Caster angle	Cab-chassis specifications	2°55' ± 45'
	Except cab-chassis specifications	3°15' ± 45'
Kingpin inclination angle	12°30'±30'		-

Standard value (2WD (High ride suspension specifications), 4WD)

Measurement items	Standard value		Remarks
Camber angle	0°±30'		Equally in right and left sides in 30' range
Caster angle	Cab-chassis specifications	3°00' ± 45'
	Except cab-chassis specifications	3°20'±45'
Kingpin inclination angle	12°30'±30'		-

Mark "A" at the intersection of camber measured angle value (solid line) and caster measured angle value (dotted line).

Mark "B" at the intersection of camber standard angle value (solid line) and caster standard angle value (dotted line).

Vertical distance between points A and B shows adjustment required for front cam.
Horizontal distance between points A and B shows adjustment required for rear cam.

In this case, the front cam may move in the plus direction 5 increments, and the rear cam may move in the plus direction 8 increments.

5) Final tighten the lower link cam bolt nut.

Tightening torque: 186 N・m { 19.0 kgf・m / 137 lb・ft }

6. Toe-in measurement

Toe-in measurement and adjustment should be performed with the vehicle parked on a flat plate.
If it is difficult to park on a flat plate, perform with the vehicle parked on a level floor.

1) Set the front wheel to the position for advancing straight forward.

2) Place the tip of the toe-in gauge in the center of the tire treads at a height equal to the center of the wheel shaft on the back of the left and right front wheels, and make a mark.

3) Measure distance 2 between the marks on the back of the front wheels.

4) Rotate the front wheels 180°.

5) Measure distance 1 between the left and right marks on the front of the vehicle.

6) Obtain the toe-in from the measured values.

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a. Distance 1

b. Distance 2

Toe-in (Distance 2 - Distance 1)

Standard value

0 ± 2 mm {0 ± 0.08 in}

7. Toe-in adjustment

1) Loosen the tie rod lock nut.

2) Rotate the tie rod to adjust the toe-in.

To keep the steering wheel in the center position, adjust by rotating both of the left and right tie rods only the same amount.

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Toe-in

Standard value

0 ± 2 mm {0 ± 0.08 in}

3) After adjusting the toe-in, tighten the lock nut to secure the tie rod.

Tightening torque: 98 N・m { 10.0 kgf・m / 72 lb・ft }

8. Wheel steering angle adjustment

1) Adjust the wheel steering angle.

The wheel steering angle is not adjustable, but if there is significant left/right difference, inspect the suspension arm, knuckle, tie rod, etc., for damage.
If an abnormal condition is not found as a result of inspection, in the same way as the toe-in adjustment, turn the left and right tie rods the same amount to make the left and right steering angles roughly the same.

Wheel steering angle (2WD [Except high ride suspension specifications])

Standard value

Inside 39.0° Outside 35.0°

Wheel steering angle (2WD [High ride suspension specifications], 4WD)

Standard value

Inside 37.7° Outside 33.9°