Front Bogie Wheels May Be Improperly Aligned Caterpillar

Problem:

A number of pavers have been assembled with the front bogie wheels improperly aligned. the proper wheel alignment assures maximum steering performance. The AP-1000B/BG-260C utilize a steering sensor to control each of the rear wheels speed depending on the desired turning radius. The steering angle of the left front wheel is monitored by the sensor. Steering left or right will increase or decrease the speed of each rear wheel according to the desired turning radius. If the front wheels are not properly aligned, the sensor will cause the rear wheels to drive in opposition to the path of the front wheels resulting in front wheel slippage and rolling at a slightly skewed angle to the direction of travel.

Solution:

Check the front bogie wheels for proper alignment and adjust alignment as required per the following procedure.

Checking Alignment

1. Start the engine with the parking brake engaged and turn the steering wheel to adjust the front wheels so that they are straight ahead.

2. Check the two left side bogie wheels using a straight edge. The straight edge should contact the front and rear edge of both wheels.

3. Turn off the engine and re-check the left wheels to verify the straight edge is still in contact at all four points. (If the engine remains running, the front wheels may drift slightly left or right.)

4. Check the bogie wheel alignment on the right side using the straight edge. If the straight edge contacts all four points, the wheel alignment is correct.

Adjusting Alignment

1. Start the engine with the parking brake engaged and steer the wheel full left. Check the fully retracted length of the cylinder from the center of the rod bearing to the center of the lug pin. This dimension should be 526 mm. (Reference 119-8112 Bogie Group - Standard)

2. Steer the wheels straight ahead. Using a straight edge, turn the steering wheel until the front and rear edge of both wheels contact the straight edge. The relay rod may also require adjustment to achieve proper alignment.

3. Check the bogie wheel alignment on the right side using a straight edge. If it contacts all four points, the alignment is complete. If not, the relay rod from the left side bogies to the right side bogies and the relay rod from the right rear to the front wheel will require adjustment.

Calibration

Perform propel system calibrations as outlined in the Caterpillar Service Manual KENR2949 Propel Electronic Control System.

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