The Global Roamer Overdrive has bronze internal components. For this reason you must be very selective about which oil you put in your transfer case when the overdrive is installed. As specified in the installation instructions, oils rated API-GL4 are required.
If the product claims to cover both GL5 and GL4 specifications it is axle oil and NOT a suitable lubricant in our overdrives. Use of API GL5 oils may cause corrosion of thrust washers and synchromesh parts, shorten the life of the overdrive and void the warranty.
ANY OIL WHICH MEETS API- GL5 SPECIFICATION IS A HYPOID AXLE OIL AND MUST NOT BE USED IN THE TRANSFER CASE WHEN THE GLOBAL ROAMER OVERDRIVE IS FITTED!
OILS FOR USE IN GLOBAL ROAMER OVERDRIVES
Please read this document for complete information on oils for use in the SS and DS Model overdrives.