We are committed to providing you with the highest quality of kingpin repair in the industry. With over 20 years of specialized kingpin maintenance, we know our business. It’s all we do!
“Never had to change a Kingpin Before!” The number of times this statement has been spoken is baffling. Whenever there are 2 pieces of steel rubbing together there is wear. Especially when you ask one of these 2″ pieces of steel to carry 28 foot, 36 foot, 48 foot, 53 foot, and 57 foot of equipment along behind. This is only in single trailer applications, and not looking at the loads.
Standard, over the highway fifth wheels are designed to close on a 2″ kingpin. The fifth wheel engages by a various number of latches, or mechanisms depending on the manufacturer. When the kingpin has 1/8th of wear (according to DOT inspection guidelines, SAE guidelines, PMV guidelines and manufacturer guidelines) it should be replaced. When it is pushed past these parameters there are much higher fail to engage incidents and accelerated kingpin wear characteristics to both the kingpin, fifth wheel and bolster plate. When a bolster plate develops cracks, replacing the entire bolster assembly or scab plating are the only options.
Replacing kingpins on Dry Van’s and Refrigerated Trailers is labor intensive and cost prohibitive. Most shops no longer replace kingpins from above due to extremely high liability issues. There is not a respected engineer that would sign off on a kingpin replacement from above by oxy/acetylene removing the old kingpin. This causes oxidation of the existing bolster plate, making it prone to developing cracks when the new kingpin is installed. Carbon arc removal is more effective on dry vans, but becomes problematic when welding a new kingpin in and replacing existing cross members. Issues arise due to lack of clearance to properly clean and weld new material to the old material. Usually what we witness is a complete collapse of front bolster assembly due to these issues.
Refrigerated units are problematic, because most of these trailers have aluminum floors and spray-foam insulation. Aluminum floors have a tendency to develop cracks after being welded and this leads to issues with transportation of food products. Spray Foam Insulation is generally difficult to remove and clean and can be a fire hazard.
Complete bolster plate and kingpin removal and replacement is seen as the best option and may be necessary if the kingpin is allowed to remain in operation after reaching it’s 1/8th of an inch wear expectancy. If the bolster plate develops cracks, it’s game over and a complete bolter plate assembly or scab plate are the only options. This entire bolster plate replacement can run $3-5k and could mean the trailer is laid up for extended periods while ordering a new bolster plate assembly.
With the Kingpin Specialists’ program these costly and sometimes scary options can be removed. Fleets that have been on our program have seen up to 15 years life expectancy on refrigerated units and 20+ years on dry vans. All for a fraction of the cost of replacing 1 fifth wheel and 1 kingpin, instead of performing regular kingpin maintenance.