Cummins/Onan — Changing the Crankcase Oil
Maintenance
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Procedure
- Drain and replace the crankcase oil after the first 50 hours of operation and at scheduled intervals.
- Drain while the engine is still hot.
- Refill with the correct SAE grade and API designation oil.
Specs & values
- Oil capacity 3 US quarts (2.84 litre) including filter
Source: Cummins/Onan service 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.