Product Description
CUMMINS 5259499 OEM REAR MAIN CRANKSHAFT SEAL – RAM 5.9L/6.7L (1989–2018)
Stop rear main oil leaks the right way with the genuine Cummins 5259499 rear main crankshaft oil seal. This OE seal restores a factory-tight seal at the back of your 5.9L or 6.7L Cummins, protecting your clutch or torque converter from oil contamination and keeping your Ram ready for towing, work, and daily driving.
Why choose genuine Cummins 5259499?
- OE engineering: Built to Cummins factory specifications for B-series 5.9L & 6.7L engines.
- Leak-free sealing: Helps stop oil seepage at the rear crankshaft, protecting the flywheel/flexplate area.
- Correct fitment: Designed for 1989–2018 Dodge/Ram 2500 & 3500 with 5.9L or 6.7L Cummins (verify by VIN/ESN).
- Installer ring included: Supplied with the cardboard installer ring for square, even installation.
- Trusted reliability: Genuine Cummins materials and quality control for long service life.
Fitment – 1989–2018 5.9L & 6.7L Cummins
This rear main crankshaft seal is used on a wide range of B-series Cummins applications. Typical automotive fitment includes:
- 1989–1993 Dodge D/W 250 & 350 – 5.9L Cummins (12-valve)
- 1994–2002 Dodge Ram 2500/3500 – 5.9L Cummins (12-valve & 24-valve)
- 2003–2007 Dodge Ram 2500/3500 – 5.9L Cummins (common-rail)
- 2007.5–2018 Ram 2500/3500 – 6.7L Cummins
Important: Always confirm by engine serial number (ESN) or VIN, especially on mixed-fleet or industrial/off-highway applications.
Cross-reference & related Cummins parts
When servicing the rear of the engine, many techs also replace related Cummins OE seals and gaskets for a complete repair:
- CUMMINS 4890833 OEM REAR MAIN CRANKSHAFT OIL SEAL – RAM 6.7L (2007.5–2018) / SELECT 5.9L BY ESN – alternate OE rear main seal used on select ISB 5.9L/6.7L applications (verify by ESN).
- CUMMINS 4947667 OEM REAR MAIN SEAL COVER GASKET – 5.9L (1989–2002) – rear cover gasket often replaced when the rear seal housing is removed.
- CUMMINS 3800487 OEM LOWER ENGINE GASKET KIT – RAM 5.9L (1998.5–2002) – complete lower-end gasket kit for VP44-era 5.9L when doing a full bottom-end refresh.
Installation notes
- Inspect the crankshaft sealing surface for grooves or damage. If the surface is worn, a repair sleeve style kit may be required instead of this bare seal.
- Use the included installer ring or a proper Cummins installation tool to press the seal in square and to the correct depth.
- Lightly oil the sealing lip; do not grease the outer shell or distort the seal during installation.
- Clean the bellhousing area thoroughly and verify other potential leak sources (cam plug, rear cover gasket, valve cover, etc.) before final assembly.
- After the first few heat cycles, re-check for any signs of seepage around the rear main area.
Specifications for cummins 5259499
| Attribute | Value |
|---|---|
| Brand | Cummins (Genuine OEM) |
| Part Number | 5259499 |
| Product Type | Rear main crankshaft oil seal |
| Engine Family | Cummins B / ISB / 5.9L & 6.7L |
| Typical Automotive Applications | 1989–2018 Dodge/Ram 2500 & 3500 with 5.9L or 6.7L Cummins (verify by VIN/ESN) |
| Includes Installer Ring | Yes – cardboard installer ring |
| Material | High-temperature elastomer sealing lip with steel outer shell |
| Cross Reference (ID only) | 5259499, 3973745, 4955566, 3934486, 3925529, K5259499 (equivalent or superseded numbers – verify fitment) |
| E-Codes / Emissions Notes | Used on various on-road and off-road B-series applications; specific E-codes not published – always confirm by ESN. |
| Shipping Weight | Approx. 0.26 lb (single seal) |
| Package Dimensions | Not explicitly specified; ships in protective Cummins packaging. |
| Shipping Info | Ships from CPP Diesel; shipping calculated at checkout based on destination and service. |
| UPC | Not specified by manufacturer |
| GTIN | Not specified by manufacturer |
| Prop 65 | Not specified by manufacturer. For more information, see www.P65Warnings.ca.gov. |
FAQ – CUMMINS 5259499 REAR MAIN SEAL
Will this fit my 1989–2018 5.9L/6.7L Cummins Ram?In most cases, yes. Cummins 5259499 is commonly used as the OE rear main seal on many 1989–2018 Dodge/Ram 2500 & 3500 trucks equipped with the 5.9L or 6.7L Cummins. Because there are ESN-based exceptions, we always recommend confirming fitment by VIN or engine serial number before ordering.
