Detroit Diesel — Remove the Cup Plugs
Repair & overhaul · Rear oil gallery cup plugs
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Do NOT drill through the cup plug to attach a slide hammer or similar device.
- Make sure to not damage the plug bores or the sealing surfaces of the pan rails.
Procedure
- Apply the parking brake, chock the wheels, and perform any other applicable safety steps.
- Disconnect vehicle battery power.
- Remove the transmission and clutch. Refer to the applicable vehicle service manual.
- Remove the flywheel. Refer to section 1.12 of the MBE4000 Service Manual (6SE412).
- Remove the oil pan. Refer to section 3.1 of the MBE4000 Service Manual (6SE412). Do NOT remove the Oil Pressure Limiting Valve at this time.
- Support the engine with jack stands under the cylinder block pan rails without damaging the pan rail sealing surfaces.
- Remove the rear engine mounts. Refer to the applicable vehicle service manual.
- Remove the flywheel housing. Refer to section 1.16 of the MBE 4000 Service Manual (6SE412).
- If equipped, remove and discard the bracket and epoxy retaining the two rear cup plugs.
- Do NOT drill through the cup plug to attach a slide hammer or similar device.
- Use a punch or chisel to hit the bottom of the cup plug near one side to turn it sideways.
- Grab the plug with pliers and carefully pull the cup plug from the cylinder block.
- Using a dry shop towel, clean both cylinder block plug bores so they are clean and dry.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Detroit Diesel 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.