Fontaine

sd mm 31.02.003

    Warning: All fifth wheel maintenance, adjustment, and rebuilding must be done only by a qualified mechanic. Improper or incomplete procedures could result in a possible disengagement of the trailer from the tractor, which could result in personal injury or property damage.

    Parts are under spring compression. Wear safety goggles while servicing the fifth wheel. Failure to do so can result in personal injury, due to parts ejecting with force.

  1. Disconnect the tractor from the trailer. For instructions, see the 108SD and 114SD Driver's Manual.
  2. Thoroughly steam clean the fifth wheel.
  3. Check for cracks in the fifth wheel assembly, mounting brackets, and mounting parts.
  4. Ensure that both bracket pins are in place and secured by retainer pins and cotter pins. See Fig..

    Note: 6000 Series shown; 7000 Series fifth wheels use similar parts.

    1. Wedge Stop Rod Nut

    2. Flat Washer, 5/8"

    3. Wedge Stop Rod Spring

    4. Wedge Stop Rod

    5. Grease Fitting

    6. Bracket Pin

    7. Bracket Retainer Pin

    8. Cotter Pin, 3/16" x 1"

    9. Bumper Spring

    10. Handle Spring

    11. Bolt, Secondary Safety Lock

    12. Flat Washer

    13. Secondary Safety Lock

    14. Bushing, Secondary Safety Lock

    15. Hex Locknut

    16. Pull Handle

    17. Bolt, Bumper

    18. Bushing

    19. Bumper

    20. Timer Spring

    21. Timer

    22. Operating Handle

    23. Bolt, Operating Handle

    24. Bushing, Operating Handle

    25. Hair Pin Cotter

    26. Wedge

    27. Step Jaw

    Fig. 1, Fontaine Fifth Wheel

  5. For fifth wheels equipped with bracket liners, rock the fifth wheel. If it does not rock freely, remove the top plate and inspect the bracket liners. Replace liners that are broken or less than 0.125 inch (3 mm) thick at the top of the liners. For the liner replacement procedure, see the Fontaine website, www.fifthwheel.com.
  6. Check the jaw and stationary jaw for mushrooming, and check that the serrations at the jaw and wedge are in good condition.
  7. Test the secondary safety lock latch for ease of operation.
  8. Check for loose nuts or bolts on the fifth wheel and the mounting. Set a torque wrench to the maximum torque value for the bolt being checked, and confirm that the torque is to specification. Do not loosen the bolt to check the torque. For torque specifications, see of the vehicle Workshop Manual.
  9. Check all springs to see if they are securely fastened, and are not deformed.

    10. Warning: Do not disassemble the fifth wheel to inspect the springs. The springs are under extreme pressure, and could cause serious injury.

  10. Check the wedge adjustment.
    1. Close the fifth wheel on a standard 2-inch (50-mm) kingpin or similar 2-inch (50-mm) diameter shaft so that it locks.
    2. Push on the wedge stop rod with hand pressure. It should move in 1/4 inch (6 mm) and spring back out on release.
      If the free travel is not 1/4 inch (6 mm), adjust the distance to 1/4 inch (6 mm) by turning the wedge stop rod, on the right side of the top plate, clockwise to reduce the gap and counter-clockwise to increase it.
  11. Replace cracked, worn, or damaged parts with new parts. Replace all loose mounting bolts with 5/8–11 SAE grade 8 bolts, grade C locknuts, and hardened washers. Do not re-use bolts, nuts, and washers on fifth wheel mountings.
  12. After inspecting the fifth wheel, lubricate all moving parts with a chassis or multipurpose grease. Apply a generous coating of grease to the top plate to fill the grooves, or depressions, on the top plate. See Fontaine for lubrication instructions.
Note:
Parent topic: Fifth Wheel Inspection
Document Number: 0000119730
Manual Publication Date: 2024-05-23
Topic Publication Date: 2024-10-30