Currently, exhaust brake usage can cause high temperatures in the automatic transmission due to torque converter slippage. Only 10 to 80 of the retarding force is transferred through the fluid coupling of most torque converters. The BD AutoLoc commands the lock - up clutch of the torque converter to stay engaged when the BD Exhaust Brake is activated. This allows up to 100 of the retarding force to be transferred while in 3rd and 4th gear. Also, transmission oil temperatures will remain low because of little or no slippage occurring in the converter in these gears.