TM 9-2320-209-20-3-1 c. Replacement. 1. Place intake manifold heater elbow gasket (1) on intake manifold heater elbow studs (2). 2. Put intake manifold heater elbow (3) on intake manifold studs (2). 3. Using 1/2-inch wrench, screw on and tighten four nuts and lockwashers (4). GO TO FRAME 2 TA 051721 4-138