TM 5-3895-382-24 Synthetic Base Stock Oils Synthetic   base   stock   oils   are   acceptable   for   use   in Caterpillar  engines  and  machines  if  these  oils  meet  the performance  requirements  specified  by  Caterpillar  for  a particular compartment. Synthetic base stock oils generally outperform non-synthetics in two areas: Improved low temperature viscosity characteristics, especially in Arctic conditions Improved   oxidation   stability,   especially   at   high operating temperatures Some    synthetic    base    stock    oils    have    performance characteristics  that  enhance  the  service  life  of  the  oil. However, Caterpillar does NOT recommend the automatic   extension   of   oil   drain   intervals   for   any   oil, including synthetic base stock oils.  For Caterpillar diesel engines, oil drain intervals can only be adjusted through an   oil   analysis   program   that   contains   the   following elements:   oil   condition   and   wear   metals   (Caterpillar SOS    Oil    Analysis    preferred),    trend    analysis,    fuel consumption, and oil consumption. Re-Refined Base Stock Oils Re-refined   base   stock   oils   are   acceptable   for   use   in Caterpillar  engines  and  machines  if  these  oils  meet  the performance  requirements  specified  by  Caterpillar  for  a particular   compartment.      Re-refined   oils   can   be   used exclusively  in  a  finished  oil  or  in  combination  with  new base    stocks.        The    US    Military    and    other    heavy equipment manufacturers have also accepted the use of re-refined base stock oils with the same criteria. The  re-refining  process  should  be  adequate  to  remove all wear metals and oil additives that were present in the used     oil.          This     type     of     re-refining     is     generally accomplished   by   vacuum   distillation   and   hydrotreating the  used  oil.    Filtering  alone  is  inadequate  for  producing a high quality re-refined base stock from used oil. After-Market Oil Additives Caterpillar does NOT recommend the use of aftermarket oil     additives.          After-market     oil     additives     are     not necessary  to  achieve  life  predictions  or  to  achieve  rated performance.  Fully formulated finished oils are made up of base stocks and commercial additive packages. These   additive   packages   are   blended   into   the   base stocks   at   precise   percentages   to   provide   finished   oils with    performance    characteristics    that    meet    lubricant industry standards. Lubricant industry standard tests do not exist to evaluate the performance of after-market oil additives. There  are  also  no  lubricant  industry  standard  tests  to evaluate the compatibility of these after-market additives in    a    finished    oil.        After-market    additives    could    be incompatible  with  the  finished  oil  additive  package,  and lower   the   performance   of   the   finished   oil.      The   after- market additive could fail to mix with the finished oil, and produce     a     sludge     in     the     crankcase.          Caterpillar discourages  the  use  of  after-market  additives  in  finished oils. To   achieve   all   the   performance   that   was   built   into   a Caterpillar engine, follow these guidelines: Select the proper Caterpillar oil or commercial oil that meets the compartment specifications. Select   the   proper   oil   viscosity   based   on   the Engine Oil Viscosity Chart in this manual. Service  the  engine  at  the  specified  interval  with new oil and oil filter. Perform  maintenance  at  the  intervals  specified in this manual. Drum   Support   Housing,   Vibratory   Housing,   Drum Gear Reducer Use  gear  type  oils  with  an  ISO  code  of  19/16  or  better for cleanliness levels.  Based on recent test data, this oil type   with   the   proper   viscosity   will   fulfill   the   lubricant requirements. For commercial oils use API GL-5 or MIL-L-2105C. Maintenance Section Lubricant Specifications 1-39