A seal device for preventing entry of debris into a rotary cutter drive housing when a shock protection device having frangible drive features is removed after having fractured the drive features following a driveline overload condition. The housing includes an upwardly facing opening through which a drive shaft for the cutter extends. The drive shaft rotationally engages the shock protection device for driving the rotary cutter. The seal device is disposed in the upwardly facing opening beneath the protection device and includes drive means for rotation in unison with the drive shaft. The seal device further includes a seal interface for sealing interface with a contact seal disposed on the inner circumference of the opening thereby preventing the entry of debris into the housing.