Passenger Car Steering Systems

Klotz steering system test benches for cars and trucks are used by many renowned manufacturers: End-of-line test benches, quality assurance test benches, development test benches and final assembly lines for servo and recirculating ball steering systems. Properties such as the performance, leak tightness, acoustics, fatigue strength, load capacity and other criteria are tested.
In addition to systems for hydraulic steering systems (HPS), Klotz has also been building assembly and testing systems for EPS and/or EPAS steering systems and components since 2006. Klotz has a strong team and a comprehensive library of solutions for test bench software systems. External bus simulation for FlexRay and CAN systems are an integral feature of many systems.
Klotz has implemented test benches and assembly lines for both Rack-EPS (R-EPS) and Column-EPS (C-EPS) technologies.
Klotz systems offer a very high availability under continuous operation (24 h).
The assembly and testing systems are in use around the world, for example in Brazil, China, Germany, France, Russia and the Czech Republic.

End-of-Line test station for electric power steering systems (EPS/EPAS)

100 % testing of EPAS systems, integrated in the assembly line. In addition to the function tests, the test bench also performs an acoustic test on every steering gear.

The new generation of Klotz steering gear test benches are based on many years of practical experience as well as the results of research and development studies. Computer-controlled function tests can be performed on mechanical and electromechanical rack-and-pinion steering gears. The scope of delivery also includes implementation of the external bus simulation (CAN/Flexray).

The test bay integrated in final assembly generally consists of several autonomous test benches, each equipped with a hydraulic unit for the clamping functions.

Every test bench primarily consists of:

  • Base with base frame and pinion drive frame
  • Electro-mechanical or hydraulic load units on the left and right
  • Docking unit for vehicle points on the left and right
  • Drive unit input shaft with centring gripper as well as torque and angle sensors
  • Units for docking the power and bus connection to the steering column
  • Safety systems
  • Control cabinet, PC and control panel
  • Flexible and expandable test bench software, with all quality data saved to a central location





Final assembly and testing of electric power steering drives

Assembly line for joining and screwing the motor and ECU, welding of contacts, surface pre-treatment, applying protective covers, flashing the ECU and leak tightness testing as well as function testing.

Specifications: High technical availability, cleanliness and ESD requirements.

Durability Test Bench for Rack and Pinion Steering Gears

This test bench is used to carry out durability tests of manual and power-assisted rack and pinion steering gears. Static and dynamic tests up to 30 Hz tie rod load run computer-controlled. The drive unit can be adjusted in 4 axes, the load input unit in 2 axes. By TCP/IP interface, the status of the current tests can be queried by any computer concerned.

Durability Test Bench for Rack and Pinion Steering Gears

This test bench is used to carry out durability tests of manual and power-assisted rack and pinion steering gears. Static and dynamic tests up to 30 Hz tie rod load run computer-controlled. The drive unit can be adjusted in 4 axes, the load input unit in 2 axes. By TCP/IP interface, the status of the current tests can be queried by any computer concerned.

Test Bench for Single and Continuous Tests of Axial Joints

The axial joint test bench subjects different axial joints to severe single and continuous load tests. Duty cycles, angular movements, temperature and air humidity can be preselected freely. Failure criterion is the axial play that develops or the breakage of the axial joint.

Technical brief description:

The test bench allows the simultaneous test of a maximum of 4 axial joints.
The axial load for each joint and the angular movement for all joints together are applied by servo-type hydraulic cylinders. The control of axial load and angular movement is optionally linear or sinusoidal.
Each test location has a separate support and individual test adapters. This allows simultaneous test of different axial joints.
The axial play is determined by measuring the movement between housing and joint bar at a given load on the axial joint. If a joint is defective, the corresponding cylinder is cut off. Time of failure, number of cycles and development of axial play are recorded.

Power Steering Test Bench for 100 % Testing in Assembly Line

The test bench carries out fully automatic functional testing of hydraulic rack and pinion steering gears. Due to the automatic identification of the steering gear types, the test bench adapts virtually automatically to different steering models. So only few, or ideally no, manual operations are required when model change is carried out.

The integrated tool magazine minimizes the non-productive times and the work to be performed by the operator during tool change or resetting. This increases productivity and efficiency significantly. Because of the short resetting times, even small batch sizes can be made economically.

Power Steering Test Bench for Product Development

This power steering test bench tests different rack and pinion steering gears, with the change-over times being short. Thus, it is above all suitable for steering gear development. Servo cylinders controlled by PC serve as rack load input unit.

The drive head for the input shaft – with AC servo motor and torque measuring shaft – is mounted on an XYZ slide and can be swivelled in 2 planes. Standard tests can be preselected by menu, special tests can be drawn up by PC.

Test Bench for Servo Steering and Servo Pump

Steering Gear Test Bench with Double Drive Shaft


The test bench should perform manual and computer-controlled functional tests on mechanical and hydraulic steering gears. Both rack and pinion and recirculating ball steering gears have be tested with this. Clamping fixtures and coupling units should be easy to handle to provide high flexibility for changing the different types.

Following function tests are to be carried out:

  • steering angle
  • steering distance
  • pressure (hydraulic control)
  • oil leakage loss
  • hydropulse frequency
  • play measurement
  • steering-moment characteristic
  • friction-moment characteristic
  • pressure-steering wheel-moment characteristic
  • rack shifting-load characteristic
  • pressure allowance
  • bush play
  • pinion torque

Manual and computer-driven strength test:

  • input torque test as prescribed
  • input torque test until failure


To ensure required accuracy for friction moment and steering-gear rupture moment test stand had to be equipped with two measuring trains. Moments of approx. 0.5 to 50 Nm are measured in small measuring train. For moments of up to 750 Nm occurring during rupture test big measuring train is used. System is SPS controlled. During automatic operation integrated computer takes over test programme, data acquisition, preparation and output. Various steering gears may be tested on unit. Corresponding adapter devices are provided.

To test hydraulic steering gears test stand may be equipped with controllable oil supply assembly as well as reception device and drive of original oil pump.


Fully Automatic Assembling Equipment for Steering Valves

The equipment recognizes fully automatically the position of steering valves in containers and fits these with controlled force on rack and pinion steering gears. In addition, grease is applied to the rack and the support bearing is supplied by the equipment. For handling the components, an industrial robot is used which is fitted with an imaging system and a force-moment sensor.

The whole equipment is completely integrated into an existing assembly line and operates on a three-shift basis.

The result is a constantly high quality at a cycle rate of 23 seconds and reduction of the reject rate to a minimum.

100 % Check of Power-Assisted Steering Gears

The testing machine performs in a single, compact and high-precision machine all functional tests of completely assembled rack and pinion power steering gears. The test steering gears are fed, coupled and tested fully automatically. The test results are stored on data medium and network server. As the steering gear types are identified automatically, types can be changed without manual intervention.

Automatic Steering Gear Test Stand

Test Equipment for Steering Input Lines

This test bench serves to investigate wear on steering input lines. Optionally, the test is controlled based on turning angles or torques. Within a T-slot range, the drive and load input unit is fixed in the desired position. Turning angle and turning rate are preselected by input in an NC. Different moments of load can be preset for right-hand and left-hand rotation.

Hand-Operated Steering Test Stand