Cummins/Onan — Drain Lubricating Oil
Maintenance · lubricating oil system
From a Cummins/Onan owner's manual covering: 4B3.9, 4BT 3.9, 4BTA 3.9, 6B5.9, 6BT 5.9, 6BTA5.9, B3.9, B5.9, C8.3. Check it applies to your exact model before use.
Applies to: Cummins/Onan 4B3.9, Cummins/Onan 6BTA5.9, Cummins/Onan B5.9 engine
Before you start
- Avoid direct contact of hot oil with your skin.
Procedure
- Operate the engine until the water temperature reaches 60 C [140 F]. Shut the engine off.
- Remove the oil drain plug and drain the oil into a suitable container.
- Clean the sealing surface, check the oil drain plug threads, and install the drain plug.
- Torque drain plug: steel pan 80 N*m [59 ft-lb]; aluminum pan 60 N*m [44 ft-lb].
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Drain oil only when it is hot
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.