TM 9-6115-658-13&P 2-20 Table 2-2.  Operator Preventive Maintenance Checks and Services – (continued) ITEM NO. INTERVAL LOCATION PROCEDURE NOT FULLY MISSION CAPABLE IF: ITEM TO CHECK/SERVICE 34 After LUBRICATION SYSTEM a. Inspect lubrication system for leaks, damaged, loose, or missing parts. b. Check oil level. c. Check engine oil for contamination. Class III leaks, damaged, loose, or missing parts. Oil level is below add level. Engine oil shows signs of contamination. 35 After CONTROLS AND INDICATORS Check all controls and indicators for   Damaged or missing parts. Controls or indicators damaged or missing. TRAILER 36 After SWITCH BOX ASSEMBLY   a. Check for loose or missing hardware. b. Check for damaged indicator lights. c. Check hinges and clamping catches. d. Check for loose or damaged switches. e. Check output terminals and connectors for damaged or missing hardware. Two or more mounting bolts missing. Indicator lights are damaged. Switches loose or damaged. Output terminals   or connectors will not properly secure load cables.