The Chrysler 68RFE Low/Reverse Sprag Update replaces the failure-prone OEM low/reverse sprag with this stronger and more durable roller clutch design, ideal for high performance and towing applications.
The low/reverse clutch is on only when the output shaft is turning below 150 rpm. The clutch releases back onto the low/reverse sprag during hard acceleration or burn-outs after the driveshaft speed reaches 150 rpm.
The OEM sprag will not stand up to such stresses for long before failure results with the loss of 1st and 2nd gear starts.