Ladder bar installation is a complex process requiring precise measurement and adherence to specific procedures to ensure optimal vehicle performance. These triangular-shaped traction devices are utilized to control rear axle housing wrap-up, enhancing traction, particularly in drag racing applications. Successful installation necessitates careful attention to chassis alignment, component placement, and welding techniques. This article details the steps involved in ladder bar installation, emphasizing safety precautions and the importance of accurate measurements.
Understanding Ladder Bars and Their Function
Ladder bars function by preventing excessive suspension wrap-up. They achieve this by exerting an upward force on the frame at the point where the upper and lower bars intersect – a point referred to as the “pickup point.” This action effectively lifts the front of the car, improving traction by applying a downward force on the tires. The bars themselves are typically welded to both the rear axle housing and the vehicle frame. They are characterized by their triangular shape and connection method, which relies on welding.
Preliminary Steps and Safety Precautions
Prior to commencing installation, several preparatory steps are crucial. It is recommended to perform the work in a dry, well-lit shop with a level or near-level floor. Proper supports and jack stands must be used not only for construction purposes, maintaining chassis level, but also for safety. Throughout the installation process, wearing eye protection is essential.
The documentation stresses the importance of taking one’s time and exercising good common sense. All measurements should be checked and re-checked before any cutting or welding is performed. If any questions or concerns arise during the installation, it is advised to stop and consult the manufacturer’s technical support line at 610-948-7303. A cautious approach, including tack welding components initially, allows for easier correction of mistakes.
Locating the Chassis Center Line
Accurate chassis alignment begins with locating the chassis center line (C/L). The C/L represents the midpoint running the length of the vehicle and is fundamental for ensuring the frame rails are properly centered. This can be determined by dropping a plumb line from identical points on opposite sides of the car to the floor, both at the front and rear. Measuring the distance between the plumb line marks on the floor, and then finding the midpoint, establishes the C/L. This line can then be transferred to the car itself for quick re-establishment if needed.
Assembling the Ladder Bars
The ladder bars themselves require assembly before installation. Each end of the bar should be threaded, leaving approximately three-quarters of the threading available to allow for adjustment. A sheet of plywood placed on the floor provides a stable base for this assembly process. The threaded rod ends should be fully threaded, leaving room for adjustment.
Installing Frame Rails and Connectors
When installing S&W Performance Group’s direct fit frame rails, it may not be necessary to remove the floor entirely. However, notching the floor may be required for certain applications and frame rail locations. It is recommended to determine the frame rail locations before notching the floor.
Rear Housing and Shock Mount Installation
The next step involves locating the rear housing at the desired ride height and wheelbase. Lower shock mounts should then be installed to the rear housing according to the manufacturer’s instructions. A shock jig is used to determine the location of the upper shock cross member; the height of the rear of the frame rail is dictated by the height of this cross member.
Ladder Bar Mounting and Adjustment
Once the rear housing and shock mounts are in place, the ladder bar can be installed. The front brackets of the ladder bar must be bolted to the front tube(s) as per the provided instructions. Maintaining the correct height of the front of the frame rail is crucial, and this height is determined by the height of the front of the ladder bar. Maximum adjustability is achieved when the front of the ladder bar is located on the front brackets.
Final Checks and Adjustments
After installing the ladder bars, tires and wheels should be mounted on the rear housing. The suspension should then be moved through its full range of motion to check for any clearances – between the tire and body/frame, the housing and frame, and the shock and housing. If no clearance issues are identified, the car can be lowered to the ground to verify the ride height.
Fine-tuning may be necessary, including adjusting the pinion angle and preload. Summit Racing™ Double-Adjustable Ladder Bars, for example, allow for these adjustments without requiring removal of the bars from the vehicle.
Pinion Angle Measurement
Measuring the pinion angle is an important part of the fine-tuning process. This involves measuring the angle of the pinion relative to the driveshaft or crankshaft centreline, ideally at ride height with the rear end supported on jack stands or the floor. Understanding the slope of this angle is critical for optimal drivetrain performance.
Completing the Installation
The final step involves installing a roll cage or roll bar to complete the frame installation. After tack welding the cage or roll bar in place, all remaining welding – including suspension components, frame rails with cross members, and the cage or roll bar itself – should be finished.
Frequently Asked Questions
Ladder bars are described as triangular-shaped traction devices connected to the rear-end housing and the frame, typically through welding. They prevent excessive suspension wrap-up by pushing up on the frame at the forward connection point, lifting the front of the car and improving traction.
Conclusion
Ladder bar installation is a detailed process that demands precision and adherence to established procedures. Proper chassis alignment, careful assembly, and thorough checks are essential for maximizing the benefits of this traction-enhancing component. Prioritizing safety, utilizing appropriate tools, and consulting manufacturer documentation are crucial for a successful installation. The documentation emphasizes the importance of taking one’s time and seeking expert assistance when needed.