2 1EVERY 6 MONTHSChange gear oil in the tumbler shaft gear reducer.1. Remove the drain plug (located at the bottom rear of the reducer).2. After oil is completely drained replace the drain plug.3. Remove the vent plug and pour in 1.4 liters of Mobil Oil DTE HH5G (I.S.O. viscosity grade 460),SAE 90, or equivalent.C. ADJUSTMENTS7 DAYS AFTER INSTALLATION and EVERY 6 MONTHS THEREAFTERInspect bolts, nuts, screws, (bearing set screws), nonpermanent gas connections (i.e., unions, shut-offvalves, orifices), and grounding connections. Fan (impellor) V-belts, along with the motor and drive beltsshould be examined and replaced if necessary. Tighten loose V-belts when necessary. Completeoperational check of controls and valves. Complete operational check of ALL safety devices (i.e., doorswitches, lint drawer switch, sail switch, burner and hi-limit thermostats).