Cummins/Onan — Lubricating Oil and Filter Change
Maintenance · Lubricating oil system
From a Cummins/Onan owner's manual covering: B3.9, B4.5, B5.9. Check it applies to your exact model before use.
Browse Cummins/Onan generators & specs →
Before you start
- Used engine oil can be carcinogenic; avoid inhalation of vapors, ingestion, and prolonged contact.
- Avoid direct contact of hot oil with your skin.
Procedure
- Operate the engine until water temperature reaches 60°C [140°F] and shut it off.
- Remove the oil drain plug from the bottom of the lubricating oil pan.
- Clean the area around the oil filter head and remove the oil filter.
- Clean the gasket surface of the filter head and make sure the o-ring is removed.
- Fill the new filter with clean lubricating oil and apply a light film of oil to the gasket sealing surface.
- Install the filter as specified by the filter manufacturer.
- Check the oil drain plug threads and install the drain plug.
- Fill the engine with clean lubricating oil to the proper level.
- Operate the engine and check for leaks at the filters and oil drain plug.
Tools required
- Container that can hold at least 26 liters [27 qt] of lubricating oil
- Oil filter wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Oil drain plug torque: steel pan 80 N·m [59 ft-lb]; aluminum pan 55 N·m [41 ft-lb]
Source: Cummins/Onan owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.