MAINTENANCE SECTION II Spicer® Transmission Lubrication To insure proper lubrication and operating temperatures in  these  units,  it  is  important  that  proper  lubricants  be used and correct oil levels be maintained. Recommended Lubricants The lubricants listed below are recommended, in order of preference, for use in all Spicer mechanical transmissions, auxiliaries and transfer cases. DO    NOT    USE    EXTREME    PRESSURE    ADDITIVES, such    as    found    in    multi-purpose    or    rear    axle    type lubricants.    These  additives  are  not  required  in  Spicer transmissions, and in some cases may create transmission  problems.    Multi-purpose  oils,  as  a  group, have   relatively   poor   oxidation   stability,   a   high   rate   of sludge  formation  and  a  greater  tendency  to  react  on  or corrode the steel and bronze parts. Oil Changes We  recommend  an  initial  oil  change  and  flush  after  the transmission  is  placed  in  actual  service.    This  change should  be  made  any  time  following  3000  miles  (4827 km),    but  never  exceed  5000  miles  (8045  km)  of  over- the-road service.  In off-highway use, the change should be made after 24 hours-but before 100 hours-of service have been completed. Many  factors  influence  the  following  oil  change  periods. Therefore,   a   definite   mileage   interval   is   not   specified here.  In  general,  however,  it  is  suggested  that  a  drain and flush be scheduled every 50,000 miles (80,450 km) for   normal   over-the-highway   operations.      Off-highway uses  usually  require  an  oil  change  every  1000  hours. The oil level in the transmission should be checked every 5000 miles (8045  km)  on-highway,  or  every  40  hours  in off-highway  operation.    When  it  is  necessary  to  add  oil, we recommend that types or brands of oil not be mixed. The    correct    oil    level    in    all    Spicer    transmissions    is established by the filler plug opening. Refill First, remove all dirt around the filler plug.  Then refill the transmission with new oil.  Use the grade recommended for   the   existing   season   and   prevailing   service.      The lubricant  should  be  level  with  the  oil  fill  plug  located  on the right side of the transmission case. Overfilling Do not overfill the transmission.  This usually results in oil breakdown due to excessive heat and aeration from the churning action of the gears.  Early breakdown of the oil will result in heavy varnish and sludge deposits that plug up  oil  ports  and  build  up  on  splines  and  bearings.    Oil overflow   escapes   onto   the   clutch   or   parking   brakes, causing additional trouble. TEMPERATURE GRADE TYPE Above 0° F (-18°C) SAE 30, 40, or 50 Heavy duty engine oil meeting MIL-L-2104D or MIL-L- 46152B, Below 0° F (-18C) SAE 30 API-SF or API-CD NOTE:  Oils meeting MIL-L-2104B and 2104C, or 46152 are also acceptable. Above 0° F (-18C) SAE 90 Straight mineral gear oil - R & O Type, API-GL-1 Below 0° F (-18°C) SAE 80 4