Sonnax offers thrust washer CH-WF-3 to replace OE thrust bearings. The OE roller thurst bearings have a high failure rate when subjected to impact loading. Many rebuilders prefer the impact resistance of the thrust washer. CH-WF-3 is .020" thicker than the OE thrust bearing, allowing resurfacing of the front cover if required. Extra shims are not required when using the CH-WF-3.
Install the thrust washer with oil grooves facing the front cover when using the OE turbine hub. Install the thrust washer with oil grooves facing turbine when using Sonnax turbine hubs.