TM 9-2320-209-20-3-4 b. Repair. FRAME 1 1. Check that upper exhaust extension (1) has no cracks, dents or holes. If upper exhaust extension is damaged, get a new one. 2. Check that weather cap (2) opens and closes freely. Put lubricating oil on hinge (3) if needed. 3. Check that lower exhaust extension (4) has no cracks, dents or holes. If lower exhaust extension is damaged, get a new one. END OF TASK 23-105