Product Description
Interstate-McBee M-3900257 Gear Housing Dowel Pin (Killer Dowel) – 89–02 5.9L Cummins
Replacement alignment dowel pin for the 5.9L Cummins timing gear housing—commonly known as the Killer Dowel Pin (KDP). Restores proper location of the timing cover/gear housing and helps prevent movement that can lead to leaks or interference with rotating components. Sold individually.
- Direct-fit: OE-style steel dowel matches Cummins reference 3900257.
- Fixes KDP issues: Ideal for engines undergoing a “KDP fix,” timing cover reseal, or front-end service.
- Durable: Precision-ground pin for correct interference fit in the housing bore.
Specifications
| Brand | Interstate-McBee |
| Part Number | M-3900257 |
| OEM Reference | Cummins 3900257 |
| Location | Timing gear housing alignment dowel (“KDP”) |
| Sold As | Each (1 dowel pin) |
Vehicle Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500 5.9L Cummins
- Model Years: 1989–1998 (12-valve 6BT) and 1998.5–2002 (24-valve ISB)
- Other B-Series applications where Cummins 3900257 is specified (confirm by ESN).
What’s Included
- (1) Gear housing dowel pin, P/N M-3900257
Recommended/Related Parts
- Timing cover gasket/seal set
- KDP retainer/tab & bolt kit (prevents future dowel movement)
- Front main seal (if servicing while cover is off)
Install Notes
- Perform with the battery disconnected and the engine cool.
- Clean the bore and inspect the housing for damage before installation.
- Drive the dowel squarely to the specified depth; do not deform the pin.
- For a comprehensive “KDP fix,” secure the dowel with a retainer/tab per service-manual guidance.
Why Buy From CPP Diesel
- ESN-verified fitment help from diesel specialists
- Fast shipping, easy returns, competitive pricing
- Deep inventory for 12V and 24V Cummins maintenance and repair
FAQ
Is this the same as the “Killer Dowel Pin”?
Yes. This is the alignment dowel in the timing gear housing that enthusiasts refer to as the KDP.
How many do I need?
One dowel pin per engine. This listing is for a single pin.
Will this fit both 12-valve and 24-valve 5.9L engines?
Yes—fits 1989–1998 12V and 1998.5–2002 24V applications where Cummins 3900257 is specified. Verify by ESN for edge cases.
