Inspection of the Toe-In
Note: The final stage manufacturer is responsible for setting the vehicle ride height with air suspension and some vehicle alignments. On full-railed chassis, this includes the final toe-in setting on the front axle. For modular style chassis, both the front axle toe-in and rear axle thrust angle settings are included.
For vehicle alignment to be accurate, the shop floor must be level in every direction. The turn plates for the front wheels must rotate freely without friction, and the alignment equipment must be calibrated every three months by a qualified technician from the equipment manufacturer. Freightliner dealers must have proof of this calibration history.
Note: Toe-in should be within 0 to 1/32 inch (0.8 mm).
- Apply the parking brake, and chock the rear tires.
- Raise the front of the vehicle until the tires clear the ground. Check that the safety stands will support the combined weight of the body, axle, and frame. Place safety stands under the axle.
- Using spray paint or a piece of chalk, mark the entire center rib of each front tire.
- Place a scribe or pointed instrument against the marked center rib of each tire, and turn the tires. Hold the scribe firmly in place so that a single straight line is scribed all the way around each front tire.
- Place a turn-plate or turntable under both front tires. Remove the safety stands from underneath the axle, then lower the vehicle. Remove the lockpins from the gauges; make sure that the tires are pointing straight ahead.
- Place a trammel bar at the rear of the front tires; locate
the trammel pointers at spindle height, and adjust the pointers to
line up with the scribe lines on the center ribs of the front tires.
See Fig.. Lock the pointers in
place. Check that the scale is set to zero.
Note: B minus A equals toe-in.
Fig. 1, Wheel Toe-In (overhead view)
- Place the trammel bar at the front of the tires and adjust
the scale end so that the pointers line up with the scribe lines.
See Fig. and Fig..
Fig. 2, Trammel Bar Positioning
Fig. 3, Setting Trammel Bar Pointers
- Read the toe-in from the scale, and compare it to the toe-in specification, see of the Recreational Vehicle Chassis Workshop Manual, or take the vehicle to an authorized Freightliner dealer. If corrections are needed, see of the Recreational Vehicle Chassis Workshop Manual, or take the vehicle to an authorized Freightliner dealer.
Note: If turn-plates or turntables are not available, lower the vehicle. Remove the chocks from the rear tires and release the parking brake. Move the vehicle backward and then forward about six feet (two meters).