Jost

p4 mm 31.07

To maintain proper fifth wheel operation, always lubricate the fifth wheel after an inspection has been performed.

Important: Lubricate the fifth wheel:

  • After power washing, or steam cleaning.

  • If the vehicle operates in harsh conditions such as salt spray from road surfaces, or in extremely dusty environments.

  • After any service that requires removal of lubricant from the fifth wheel head or components.

Warning: Failure to properly lubricate the fifth wheel could result in a possible disengagement of the trailer from the tractor, which could result in personal injury or property damage.

Lubricate the kingpin lock using a hand pump grease gun through the grease zerk on the skirt of the fifth wheel; see Fig.. Apply a light oil to all moving parts. For sliding fifth wheels spray diesel fuel on the slide path of the base plate.

  1. Jam Nut

  2. Adjustment Bolt

  3. Grease Zerk

Fig. 1, Jost Fifth Wheel

Notice: Do not use a power grease gun. The pressure will damage the lube line.

If the fifth wheel is not equipped with low-lube plates, apply a lithium-based grease with extreme pressure (EP) additive to the trailer contact surface of the fifth wheel.

If the fifth wheel is equipped with low-lube plates, the top plate only requires lubrication at the new product break-in stage. The low-lube plates require no further lubrication.

Note:
Document Number: 0000102782
Manual Publication Date: 2024-05-15
Topic Publication Date: 2025-03-11