Product Description
Interstate-McBee M-3937111 Front Crankshaft Seal — 1989–2007 5.9L Cummins (Aftermarket Replacement)
Direct-fit front main seal for the 5.9L Cummins (6BT / ISB) used in Dodge Ram 2500/3500 trucks from 1989–2007. Designed to meet OE form, fit, and function to restore proper sealing at the crankshaft nose. Sold individually.
- OE-style replacement: Matches critical dimensions for a reliable, leak-free install.
- Wide fitment coverage: Fits 12-valve (1989–1998), 24-valve VP44 (1998.5–2002), and common-rail ISB (2003–2007) 5.9L applications.
- Service friendly: Ideal for timing cover or damper service, or to address oil seepage at the front main.
- Value: Interstate-McBee quality at a budget-friendly price point.
What’s Included
- (1) Front crankshaft seal, P/N M-3937111
Vehicle Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500 with 5.9L Cummins:
- 12-Valve 6BT: 1989–1998
- 24-Valve ISB (VP44): 1998.5–2002
- 24-Valve ISB Common Rail: 2003–2007
Recommended / Related Parts
- Crankshaft damper bolt and washer (replace if stretched or damaged)
- Front timing cover gasket and crankshaft wear sleeve (if applicable)
- Front crankshaft seal installer tool
- Harmonic balancer (inspect rubber isolator for cracks/separation)
Install Notes
- Use a proper seal installer to press the seal squarely; avoid hammering.
- Inspect the crank snout for grooves; install a wear sleeve if needed.
- Clean the timing cover bore; lightly oil the sealing lip if specified by the service manual.
- Verify correct installation depth and orientation; follow Cummins torque specs for the damper hardware.
- Check crankcase ventilation (CCV) function; excessive crankcase pressure can cause repeat leaks.
FAQ
Does this include a wear sleeve or installer tool?
No. This listing is for the front crankshaft seal only. Wear sleeve and installer tool are sold separately.
How many seals do I need?
One. There is a single front main seal per engine.
Will this fit 6.7L Cummins engines?
No. This part is intended for 5.9L Cummins engines (1989–2007) only.
Specifications for Interstate-McBee M-3937111
| Brand | Interstate-McBee |
| Part Number | M-3937111 |
| UPC | Not specified by manufacturer/seller |
| GTIN | Not specified by manufacturer/seller |
| Shipping Info | Package weight: 0.20 lb (typical for front crankshaft seal). Other shipping dimensions/method: Not specified. |
| Cross Reference | OE reference: Cummins 3937111 front crankshaft seal for 5.9L 6BT / ISB engines (1989–2007). Additional cross references: Not specified. |
| E-Codes | Not specified |
| Prop 65 | WARNING: This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information: https://www.P65Warnings.ca.gov |
