SAF-Holland recommends the following steps for inspecting a rigid-mount, air cushioned pintle hook, primarily used for double and triple trailer configurations using converter dollies, as well as straight trucks such as dumps that pull rigid tongue equipment trailers. These are general guidelines; follow your specific pintle hook manufacturer’s instructions.
For proper performance, the following maintenance steps should be performed every 30,000 miles or three months, whichever comes first.
1. Check the wear on the hook portion of the pintle hook using a pintle hook gage. Replace pintle hook when horn wear exceeds 1/8 of an inch (0.125 inches) from the original surface profile.
NOTE: Contact your pintle hook manufacturer if a pintle hook guage is not available.
2. Check the pintle hook for damage. Inspect the pintle hook for any nicks, gouges, deformation or cracks, which may interfere or affect the safe use of the pintle hook. Replace the pintle hook if any damage is noted.
3. Check mounting fasteners for proper torque. Also check the mounting surface of the truck or trailer that the pintle hook is mounted to for any cracks or other indications of metal fatigue.
4. Clean and check latch and air cushioning system for proper operation. Inspect for excessively worn, damaged or missing parts. Replace as required using original parts supplied by your pintle hook manufacturer.
- Lubricate latch pivots with a light oil lubricant. Wipe away excess oil so that it does not attract sand and dirt.
- Check plunger adjustment. When properly adjusted, the plunger should tightly grip a 1.25-inch round bar when the air chamber is energized. It should retract far enough back when de-energized to allow easy removal of a 1.63-inch diameter drawbar from the pintle hook. If the plunger is out of adjustment, please refer to your manufacturer’s User Manual for the proper adjustment procedure.
- With the latch closed, measure the gap between the hook and the latch while lifting up on the latch. Replace the latch when gap exceeds 3/8 inches (0.375 inches).
5. Do not grease or lubricate the horn of the pintle hook. Doing so will attract sand and dirt, which acts as an abrasive, accelerating wear of the horn and drawbar eye.