Automatic Transmission Wear Testing

Automatic transmission wear tests from Intertek Automotive Research include a range of capabilities:

Vickers Wear (ASTM D2882 modified):
The three major OEM transmission fluid specifications include a modified version of the ASTM D2882 Vane Pump Wear test. The test is run at 6.9 MPa (1000 psi) for 100 hours. Fluid temperature is maintained at 80°C (175°F). Weights of the pump vanes and outer cam ring are measured before and after test to determine the amount of wear.

DEXRON®-VI Sprag Clutch Overrunning Wear Test (SCOWT):
The SCOWT is an OEM designed test to evaluate a fluid's anti-wear properties using a transmission one-way roller clutch. The clutch is mounted between two opposing rotation motors, which create a differential rotating speed of 16,800 rpm, and run for one hour. Weight loss of the inner race of sprag clutch is used to determine amount of wear.

Four-Ball Wear (ASTM D4172):
A modified version of this standard test is used to evaluate ATF for MERCON®. Three steel balls are clamed together and covered with the lubricant to be evaluated. A forth ball is pressed against the top of the others at a specified force of 40 Kg making a 3 point contact. The temperature is regulated at 100°C and the top ball is rotated at 600 rpm for 2 hours. Additionally the test is run at 150°C. The wear scars generated on the lower 3 balls are evaluated for size to determine relative lubricant performance.

Ford One-Way Clutch Wear:
The OWC test is a test developed by Ford for the MERCON® specifications, which is similar to the SCOWT. A one-way roller clutch is used to measure a fluid's wear resistance by evaluating the wear damage of the inner race. The evaluation is both a visual inspection and weight loss.