SSP-180 Manual Transmission Synchronizer Testing

Southwest Research Institute (SwRI) can assist lubricant manufacturers in deter-mining the performance of lubricants or synchronizers for use in light- to medium-duty manual transmissions. The SSP-180 test stand, developed in the Gear Research Institute at the Technical University of Munich, allows mounting and testing of a complete synchronizer device (up to 180 mm in diameter) from a manual transmission of choice. Load conditions associated with normal transmission use are simulated during the test. 

Installation of the ZF SSP-180 synchronizer test stand expands the Institute's ability to determine the performance of lubricants and hardware for use in light- and medium-duty manual transmissions.

Use of a hardware set of known performance (such as the Audi B-80, New Venture Gear, or Daimler Benz synchronizers) allows determination of the effects of different lubricants on synchronizer endurance. As fluid formulations change to address new or greater performance requirements in other areas of the manual transmission, information provided by the test procedures run in this stand will allow lubricant formulators to determine if synchronizer performance will remain acceptable.

Typical synchronizer engagement traces show individual shift performance data. By plotting data from the engagements over the course of the test, trend data shows whether or not performance is degrading.

The test stand consists of an electric motor, two flywheels, actuating hydraulics, an oil heating and circulation system, and a test box. The large main flywheel is connected to the electric motor via a belt-and-pulley combination to ensure a constant and stable speed source. The small flywheel is the load that the synchronizers either bring to zero speed (shift to "A" position) or accelerate to a constant speed (shift to "B" position). This is accomplished by the two ring-and-cone synchronizers mounted in the test box. The rear unit accelerates the load flywheel to synchronous speed, while the forward unit decelerates the flywheel to zero speed. The actuating hydraulics move a shift fork that engages one unit and disengages the other. During shifting, heated lubricant is sprayed onto both synchronizer units. Subjecting these units to thousands of engagements serves to test synchronizer durability.

The SSP-180 synchronizer test box is capable of utilizing a variety of test hardware, including the Audi B-80 synchronizer shown here.

This brochure was published in April 1999. For more information about SSP-180 Manual Transmission Synchronizer Testing, contact Matt Jackson, Manager, Phone (210) 522-6981, Fuels and Lubricants Research Division, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas 78228-0510.

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