FORD 2009 F-550 v.2 - Manual (Page 401)

TRANSFER CASE FLUID (IF EQUIPPED)
1. Clean the filler plug.
2. Remove the filler plug and
inspect the fluid level.
3. Add only enough fluid through
the filler opening so that the fluid
level is at the bottom of the
opening.
Use only fluid that meets Ford specifications. Refer to the Maintenance
product specifications and capacities section in this chapter.
2009 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)
Maintenance and Specifications
401