Repair And Fix it

King pins and bushings are vital steering system parts on large trucks. Regular maintenance and inspection is recommended to ensure safety of the vehicle. If replacement is required, some king pin bushing models require special tools. Tools commonly used for king pin bushing removal and replacement include a press, soft brass drift punch, and a reamer.

Hydraulic Press

A hydraulic press is often used in the removal of a king pin bushing due to the extreme difficulty that can be experienced while attempting to remove the king pin. Removal of the king pin without one is nearly impossible in large trucks like semis and buses. Using a press eliminates the need for sledgehammers and torches, and the hydraulic pressure removes the king pin with little effort. Press tool kits are also available for king pin bushings. Press tool kits are used by inserting the compression nut into a ratchet.

Soft Brass Drift Punch

A soft brass drift punch can be used in place of a hydraulic press to remove the king pin bushing. Generally, it is recommended that an air hammer be used when removing a king pin bushing with a soft brass drift punch, which will make the removal of the king pin easier. The use of a sledgehammer or traditional hammer can take a lot of strength and effort, especially on a large truck. Soft brass drift punches are the best alternative to a hydraulic press because they will not spark or damage other metal parts.

Reamer

Reamers are not used in the replacement of all king pin bushings. Half-ton and three-quarter-ton trucks use what is called a "floating" bushing, recognizable by their bronze color. Floating bushings do not require reaming because they are manufactured to the final size. One-and-one-half-ton trucks do require the bushings to be reamed, because the bushings are press-fit into the spindle. For these types of king pin bushings, a reamer is required. When reaming is required, it is important to avoid honing or burnishing the king pin bushings, which will cause damage to the bushings. Reaming is done with the use of an adjustable straight flute reamer to ensure that no parts are damaged. To use the reamer, it is inserted into the steering knuckle just until the blades touch the bushing. It is then rotated with a slight downward pressure. Applying too much press can also cause damage to the king pin. Driving with a damaged king pin is extremely dangerous, and can cause a loss of control to the vehicle, possibly resulting in an accident.

Clevis pins provide a strong joint between two or more pieces of equipment while allowing the joint to pivot. One end of a clevis pin has a flat head and the other has a taper. The tapered end aligns the holes in parts as you drive the pin into the parts. A hole in the tapered end of the pin holds a cotter pin. This keeps the clevis pin from falling out of the pivot joint. However, corrosion and pressure often make it difficult to remove a clevis pin from secured parts.

Instructions

1

Spray penetrating oil on the visible length of the clevis pin. Allow the penetrating oil to sit on the pin for five to six hours.

2

Grasp the circular end of the cotter pin (located on the tapered side of the clevis pin) with a pair of needle nose pliers. Pull the cotter pin away from the shaft of the clevis pin. Set the cotter pin aside.

3

Insert the flat end of a pry bar under the lowest part of the pivot joint. Push on the end of the pry bar to release pressure from the clevis pin shaft.

4

Align the tapered end of a drift pin with the tapered end of the clevis pin. Hit the flat end of the drift pin with a hammer to drive the drift pin against the clevis pin. Continue hitting the end of the drift pin until the clevis pin pops from the secured parts.

5

Grasp the flat head of the clevis pin with self-locking pliers. Pull the clevis pin away from the part while twisting the pin in a circular motion.

Spring pins use tension created by compression to lock tight in a hole drilled through two or more components. Before installation, the diameter of a spring pin measures slightly larger than a drilled hole. The diameter of the spring pin shrinks as it enters a drilled hole. This provides the tension necessary to keep a spring pin secure in a material. Numerous designs of spring pins are available but no matter the design, they all use the same methods of installation. Incorrectly installing a spring pin will cause its body to deform and lodge in a part before the pin seats in the material.

Instructions

1

Spread lightweight oil over the exterior surface of the spring pin.

2

Grasp the spring pin with the jaws of a pair of needle-nose pliers. Ensure that at least 1/8 inch of the pin sits past the top edge of the pliers.

3

Align the spring pin with the appropriately sized drilled hole. Tap the end of the pin extending beyond the jaws of the pliers with a ball-peen hammer. Release your grip with the needle-nose pliers when the spring pin sits tightly in the hole.

4

Set the tapered end of the spring pin set on the end of the spring pin. Hit the flat end of the spring pin set with the ball-peen hammer to drive the spring pin flush with the top surface of the drilled material.