5TH WHEEL

5th Wheel Components For Peterbilt Trucks

The 5th wheel is one of the most critical connection points on any Peterbilt tractor, responsible for securely coupling the trailer to the truck. Whether you're hauling dry van freight cross-country or running flatbed loads regionally, a properly maintained 5th wheel keeps your trailer locked in and your operation running safely. Browse our selection of 5th wheel plates, locks, brackets, and rebuild kits designed to fit Peterbilt models.

Frequently asked questions about 5th wheel parts

How often should I inspect my 5th wheel?

You should inspect your 5th wheel before every trip as part of your pre-trip routine. Check for proper lock jaw engagement, kingpin wear, and adequate lubrication on the plate surface. A more thorough inspection including bracket mounting bolts and slide mechanism should happen during scheduled PMs.

What are the signs that a 5th wheel needs to be replaced?

Common indicators include excessive play between the kingpin and lock jaws, visible cracks in the top plate or mounting brackets, difficulty locking or releasing the trailer, and unusual noise or movement during driving. If the lock mechanism no longer holds securely, replacement is critical for safety.

What is the difference between a fixed and a sliding 5th wheel?

A fixed 5th wheel is mounted in a stationary position and is common on trucks that pull the same trailer type consistently. A sliding 5th wheel can be repositioned forward or backward on the frame to adjust weight distribution across axles, which is especially useful for drivers who haul varying loads or need to meet bridge law requirements.

Other parts you might need

Shop body & chassis parts for Peterbilt trucks