Trailers equipped with sliding suspensions can redistribute cargo weight on the trailer axles by moving the suspension under the trailer chassis. Moving the suspension forward increases the weight on the trailer suspension and moving it to the rear increases the weight on the tractor. The sliding section of the suspension is locked to the trailer chassis by four retractable pins, which move in and out through holes in the two angles welded under the rear of the chassis. The four pins are interlocked to a handle extending out of the suspension frame on the driver’s side. Release of the handle and pulling the handle out, retracts the four pins and permits sliding the bogie under the trailer.
Before moving a trailer equipped with a sliding bogie, check and verify that the four locking pins are fully extended and pass through the locking holes in the slider track angles on both sides of the trailer. The locking handle must also be positioned and locked in the slider frame. Gently rock the trailer forward and backward, using the tractor power with the trailer brakes set, insuring that the locking mechanism is secure.
The sliding bogie is equipped with four hold down brackets bolted to the corners of the slider frame. These brackets wrap around the lower flanges of the track angles, welded under the trailer chassis. Check the mounting bolts and verify that the brackets are tight against the slider frame and wrap around the angle legs.
Check the locking pins, links, rods and springs for wear or distortion. Be sure all links operate the four pins and fully extend the pins through the matching holes in the angles at the same rate of travel.
Check the sub frame, track angles, gussets and welds for cracks, broken parts or welds. Repair or replace according to the suspension manufacturer’s recommendations.
TO MOVE THE SLIDING SUSPENSION UNDER THE TRAILER:
Check airlines and electrical harnesses connected to the slider frame for wear, tangles and clearance.
Align the tractor and trailer in a straight line and set the tractor and trailer brakes.
Pull the locking pin handle all the way out or up and set in the latched position on the frame to release the locking pins.
Check the area around the trailer for clearance, release the tractor brakes and slowly drive backward or forward until the suspension is in the required position. (If a manual stop bar is installed, position it at the desired location before moving the slider)
Release the locking pin handle and visually check the four locking pins for complete engagement. The main cross section of the four pins must extend completely through the matching holes in the slide track angles.
Check for locking mechanism securement by rocking the trailer forward and backward with the brakes set.
NOTE: The design and function of the welded, front and rear bogie stop tubes is to limit the normal slide range of the bogie during repositioning. The bogie stops are not intended to prohibit the suspension system from leaving the trailer body when incorrectly positioned and the four locking pins are not completely engaged in the locator holes in the slide track angles