Cummins/Onan — Lubricating Oil and Oil Filter Changing/Replacement
Maintenance · Lubricating oil system
From a Cummins/Onan owner's manual covering: K1800, K2000E, K38, K50, KT38, KTA38, KTA50, KTTA38, KTTA50, KtA38, KtA50, KttA38. Check it applies to your exact model before use.
Applies to: Cummins/Onan K38, Cummins/Onan K50, Cummins/Onan KTA38, Cummins/Onan KTA50, Cummins/Onan K38 and K50 engine
Before you start
- Avoid direct contact of hot oil with your skin.
- Fill the oil filters with clean lubricating oil before installation.
Procedure
- Operate the engine until water temperature reaches 60 C [140 F]. Shut off the engine.
- Remove the oil drain plug and drain the oil immediately.
- Clean the area around the lubricating oil filter head and the gasket surface.
- Use an oil filter wrench, Part No. 3375049, or equivalent, to remove the oil filters.
- Apply a light film of lubricating oil to the gasket sealing surface before installing the new filters.
- Fill the oil filters with clean lubricating oil.
- Install the filters as specified by the filter manufacturer.
- Check and clean the oil drain plug threads and seal surface.
- Install and tighten the oil drain plug to 100 Nm [75 ft-lb].
- Fill the engine with clean oil to the correct level.
- Operate the engine at idle to inspect for leaks; shut off and check oil level again; add oil to the high H mark.
Tools required
- 3375049 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: 100 Nm [75 ft-lb]
- Use high quality 15W-40 Amazon Amazon eBay $94.00 eBay $49.74 multi-viscosity oil such as Cummins Premium Blue
Full service-parts list: Cummins/Onan K38 →, Cummins/Onan K50 →, Cummins/Onan KTA38 →, Cummins/Onan KTA50 →
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.