TM 10-3930-671-10 Planned Maintenance and Lubrication Recommended Planned Maintenance Intervals Operating Conditions Time intervals between maintenance are largely determined    by    operating    conditions.        For    example, operation    in    sandy,    dusty    locations    requires    shorter maintenance intervals than operation in clean warehouses.    The  indicated  intervals  are  intended  for normal  operation.    To  allow  better  understanding  of  this aspect, the following clarification should be made: NORMAL OPERATION: Basically,  eight-hour  handling,  mostly  in  buildings  or  in the open air. SEVERE OPERATION: Prolonged operating hours or constant usage. EXTREME OPERATION: 1. In  sandy  or  dusty  locations,  i.e.,  cement  plant, lumber or flour mills, coal dust, or stone crushing sites. 2. High-temperature     locations,     i.e.,     steel     mills, foundries, etc. 3. Sudden    temperature    changes    (constant    trips from buildings into the open air), e.g. refrigeration plant. If your lift truck is used in Extreme Operating Conditions, you must shorten the maintenance intervals accordingly. ENSURE OPERATIONAL SAFTEY E-95