The rear flange must be removed to service the rear output seal. The flange nut is installed to 136 N-m (100 lb-ft), and the flange must be held to remove and install the nut. The flange has a raised lip, and requires GM-08614-20 Retaining Bolts and GM-08614-A Flange Retainer and Remover to be used to remove and torque the nut.