31848 Mercruiser LOCKWASHER, MOUNTING BRACKET SCREW

Diesel Engine Oil
Cat DEO (Diesel Engine Oil)
Due to significant variations in the quality and in the performance of commercially available oils, Caterpillar makes the following recommendations:
Cat DEO (Diesel Engine Oil) (SAE 10W-30)
Cat DEO (Diesel Engine Oil) (SAE 15W-40)
Cat DEO-ULS (Diesel Engine Oil - Ultra Low Sulfur) (15W-40)Note: Cat DEO-ULS multigrade is the preferred oil for use in all Cat diesel engines where SAE 15W-40 is the preferred viscosity grade.Note: Cat DEO Multigrade exceeds the requirements of the following Cat Engine Crankcase Fluid (ECF) specifications: Cat ECF-1-a and Cat ECF-2. Cat DEO Multigrade exceeds the performance requirements for the following American Petroleum Institute (API) oil categories: API CI-4, API CI-4 PLUS, API CH-4, API CG-4 and API CF. Cat DEO SAE 15W-40also passes additional proprietary tests that include the following tests: sticking of the piston ring, oil control tests, wear tests and soot tests. Proprietary tests help ensure that Cat multigrade oil provides superior performance in Cat diesel engines.Commercial Oils
Note: Non-Caterpillar commercial oils are second choice oils.
Caterpillar does not warrant the quality or performance of non-Caterpillar fluids.
Caterpillar developed the ECF specifications to ensure the availability of high performance commercial diesel engine oils in order to provide satisfactory life and performance in Cat Diesel Engines.There are three current Cat ECF specifications: Cat ECF-1-a, Cat ECF-2 and Cat ECF-3. Each higher Cat ECF specification provides increased performance over lower Cat ECF specifications. The API category of diesel engine oils that have not met the requirements of at least one Cat ECF specification may cause reduced engine life.Note: The Cat ECF-1-a and Cat ECF-2 specifications replaced the Cat ECF-1 specification on 1 March 2007.
Commercial oils that meet the requirements of the Cat ECF-1-a, Cat ECF-2, and/or the Cat ECF-3 specification are acceptable for use in theCat Engine that is covered by this publication.
The following commercial oils are the preferred commercial oils for use in the Caterpillar Engine that is covered by this publication: oils that meet the Cat ECF-3 specification and oils that meet the specifications of the API CJ-4 category. Oils that meet the requirements of the API CJ-4 category are Cat ECF-3 specification compliant.Note: The following catagories of oils are not approved for use in your Caterpillar Engine:API CF, API CF-4 and API CG-4.
In selecting oil for any engine application, both the oil viscosity and oil performance classification/specification as specified by the engine manufacturer must be defined and satisfied. Using only one of these parameters will not sufficiently define oil for an engine application.
Lubricant Viscosities
The proper SAE viscosity grade of oil is determined by the minimum ambient temperature during cold engine start-up and the maximum ambient temperature during engine operation. To determine the oil viscosity that is required for starting a cold engine, refer to the minimum temperature in Table 1. To select the oil viscosity for operation at the highest anticipated ambient temperature, refer to the maximum temperature in Table 1. Generally, use the highest oil viscosity that is available in order to meet the required temperature during start-up.
Table 1
Engine Oil Viscosities for Ambient Temperatures
Ambient Temperature
Viscosity Grade Minimum Maximum
SAE 0W-20 −40 °C (−40 °F) 10 °C (50 °F)
SAE 0W-30 −40 °C (−40 °F) 30 °C (86 °F)
SAE 0W-40 −40 °C (−40 °F) 40 °C (104 °F)
SAE 5W-30 −30 °C (−22 °F) 30 °C (86 °F)
SAE 5W-40 −30 °C (−22 °F) 50 °C (122 °F)
SAE 10W-30 −18 °C (0 °F) 40 °C (104 °F)
SAE 10W-40 −18 °C (0 °F) 50 °C (122 °F)
SAE 15W-40 −9.5 °C (15 °F) 50 °C (122 °F) S O S Services Oil Analysis
These recommendations are subject to change without prior notice. Contact your Caterpillar dealer for the most up to date recommendations.
Caterpillar has developed a maintenance tool that evaluates oil degradation. the maintenance management also detects the early signs of wear on internal components. The Caterpillar tool for oil analysis is called S O S Oil Analysis and the tool is part of the S O S Services program. S O S Oil Analysis divides oil analysis into four categories:
Component wear rate
Oil condition
Oil contamination
Identification of oilThese four types of analysis are used to monitor the condition of your equipment. The four types of analysis will also help you identify potential problems. A properly administered S O S Oil Analysis program will reduce repair costs and the program will lessen the impact of downtime.The S O S Oil Analysis program uses a wide range of tests to determine the condition of the oil and the condition of the lubricated compartment. Guidelines that are based on experience and a correlation to failures have been established for these tests. Exceeding one or more of these guidelines could indicate serious fluid degradation or a pending component failure. A trained person at your Caterpillar dealership should make the final analysis.
Always use a designated pump for oil sampling, and use a separate designated pump for coolant sampling. Using the same pump for both types of samples may contaminate the samples that are being drawn. This contaminate may cause a false analysis and an incorrect interpretation that could lead to concerns by both dealers and customers.
Refer to Special Publication, SEBU6251, "Cat