Alignment Turntable

Low-profile, rotating metal platforms that are set into the floor of a service bay, one under each front wheel of a vehicle. They allow the front wheels to turn and pivot freely during a wheel alignment.

How They Work

The turntable consists of a top plate that rotates on a bearing assembly, sitting inside a fixed base plate that is flush with the floor. When a vehicle’s tire is driven onto the turntables, the technician can easily steer the wheels left and right, allowing the alignment machine to measure caster and steering axis inclination (SAI).

Key Features & Types

• Construction: Heavy-duty steel or aluminum to support vehicle weight.
• Locking Mechanism: Most have a pin or lever to lock the plate after adjustment to prevent unwanted movement during other work.
• Slip Plate Variant: Some systems use simple, low-friction plastic slip plates instead of rotating turntables for the same purpose.
• Portable Options: Smaller, portable turntables exist for mobile or occasional use.

Main Purpose

To simulate real-world driving conditions by allowing the front wheels to turn freely. This is absolutely necessary for measuring and adjusting caster and SAI, two critical angles that change as the steering wheel is turned.

Critical User Rules

• Center Before Starting: Before driving onto them, ensure the turntables are rotated to their center position and unlocked.
• Drive Straight On: Drive the vehicle slowly and directly onto the center of each plate. Avoid turning the wheel until fully on them.
• Lock When Not in Use: Once in position for other work (e.g., adjusting tie rods), lock the turntables to create a stable platform.
• Keep Clean & Clear: Regularly clean metal shavings, gravel, and debris from the bearing mechanism to ensure smooth rotation and prevent damage.
• Use in Pairs: Always use two turntables (one per front wheel) to ensure accurate, balanced measurements.

Bottom Line

Alignment turntables are a fundamental piece of shop equipment for performing a complete and accurate wheel alignment. They enable the precise measurement of critical steering angles that cannot be assessed with the wheels pointed straight ahead, ensuring the vehicle drives and handles correctly.