The transmission is filled with Penrite Synthetic 5 SAE 5W – 60 Oil. This oil can be substituted by Mobil 1, 5W – 50 (for Cold climates) or Mobil 1, 15W – 50 (for Hot climates) use only these oils unless instructed otherwise for correct servicing, draining & refilling procedures please read the instructions in the manual supplied. NOTE: Never allow contaminants to enter the transmission.