Struts in the MD behave like the “shoes” in a hydrodynamic thrust bearing, so most of the time, they are held out of contact with the notch plate during overrunning by the oil. Long term overrun tests show wear on the notch plate and strut which ranges from slight polishing to non-visible or detectable. in properly lubricated MDs we have experienced no degradation of the lock-up function after extended overrunning.