How can the answer be improved?. Manual transmission fluid can vary, however, using either plain motor oil, a transmission oil known as heavyweight hypoid gear oil, or automatic transmission fluid. The type of transmission fluid to use in vehicles with standard transmissions can usually be found in the maintenance section of the owner’s manual.. Transmission oil is a mixture of base oil and additives with very good anti-wear and anti-scoring properties and good stability to thermal oxidation. Manual transmissions use a variety of oils: regular motor oil, heavyweight hypoid gear oil or even automatic transmission fluid in some cases.. It is important to use the correct fluid oil in you manual transmission, the vehicle manufacturers have done extensive testing to specify the correct fluid. The oil is designed to reduce friction and provide necessary cooling. Information is provide for most vehicles.. Some manual trans. take 10w30 motor oil some take dextron auto trans fluid some take hypoid oil. It can be different in the same year, what is in there is correct regardless what the store/manual says.. Manual transmission fluid is an oil, thicker than engine oil and will be given a number in your vehicle service manual prefixed by two or three letters. Do not mistake it as oil for the engine as it will seriously reduce the vehicles life.. MAKE MODEL / YEAR Symbol Fluid Specification Valvoline Product Chrysler Trucks all vehicles except as noted NV 1500 manual Transmission ….