Product Description
Interstate-McBee M-3903463 Access Hole Cover – 89–98 5.9L Cummins 12V
OE-style access hole cover for the Cummins B-Series gear/timing housing access port. Built as an aftermarket replacement to the Cummins 3903463 cover, this Interstate-McBee component seals out dirt and debris and restores proper service access on 1989–1998 Dodge Ram 2500/3500 5.9L 12-valve applications.
- Direct OEM cross: Replaces Cummins 3903463.
- Correct fit, reliable seal: Designed for the B-Series gear/timing housing access port.
- Aftermarket value: OEM-equivalent performance at a lower cost.
- Service-friendly: Restores convenient access for timing/inspection procedures.
Specifications
| Brand | Interstate-McBee |
|---|---|
| Interstate-McBee P/N | M-3903463 |
| OEM Cross | 3903463 (Cummins) |
| Location | Gear / timing housing access port (front gear cover area) |
| Seal / O-Ring | Use with seal 3903475 (sold separately) |
| Primary Engine | 5.9L Cummins 12-valve (B-Series) |
What’s Included
- (1) Access hole cover (seal 3903475 sold separately)
Vehicle Fitment
Always verify by Engine Serial Number (ESN) for edge cases or mixed components.
- Dodge Ram 2500/3500 5.9L Cummins (12-Valve): 1989–1998
- Additional applications: Used across Cummins B-Series families (4B/6B/6C) and select ISC/industrial engines; confirm by ESN.
Installation Notes
- Clean the housing bore; remove any old seal residue and debris.
- Install a new seal (3903475) if worn or damaged.
- Hand-tighten/seat the cover firmly; avoid over-tightening. Follow Cummins service procedures.
Warranty
Interstate-McBee new engine parts typically include up to 24-month coverage from date of installation. For specific terms and exclusions, refer to the manufacturer’s warranty policy.
Cross-Reference & Related
- OEM Cross: Cummins 3903463 (Access Hole Cover)
- Related Seal: Cummins 3903475 (Access Cover Seal)
- Note for 2003–2018 common-rail models: These engines use a different CP3 access cover (e.g., 4935281).
Why Buy From CPP Diesel
- ESN-verified fitment support from real diesel techs
- Fast shipping and hassle-free returns
- Deep Cummins B-Series inventory to complete your repair
FAQ
Will this fit my 1989–1998 12-valve 5.9L Cummins?Yes. M-3903463 cross-references Cummins 3903463 and is used on 1989–1998 Dodge Ram 5.9L 12-valve applications. Verify by ESN if components were swapped.
Is the seal included?
No. The cover and seal are separate. Use 3903475 as the matching seal/O-ring.
Where does this part install?
It closes the gear/timing housing access port, helping keep contaminants out while preserving service access.
What about 1998.5–2002 or 2003+ trucks?
Late-1998.5–2002 24-valve and 2003+ common-rail engines often use different covers. For 2003–2018 CP3 applications, reference Cummins 4935281.
Any torque spec?
Hand-tighten/seat per Cummins service manual. Do not over-tighten plastic or composite covers.
