Product Description
Cummins 3937111 — Genuine Front Crankshaft Seal Service Kit for 5.9L Cummins
MPN: 3937111 | Also Known As: front main seal, crank seal, front crankshaft seal kit | Supersedes/Cross-Refs (ID): 3904353, 3900709
Genuine Cummins front crankshaft seal service kit for B-Series 5.9L engines. Restores a leak-free seal at the crank nose and timing cover. Direct-fit for 1989–2007 5.9L Ram 2500/3500. Includes seal and Cummins’ depth/installer components for correct, damage-free installation.
Features & Benefits
- OE sealing material designed for heat, pressure, and vibration in diesel duty.
- Service kit format with installer/depth tools for consistent seating.
- Direct-fit replacement for 5.9L 12-valve and 24-valve applications (non-CR & 2003–2007 CR).
- Helps prevent oil leaks that can foul the damper and accessory drive.
- Backed by Cummins for fit, function, and longevity.
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1998 | 5.9L 12V (6BT) | Ram 2500/3500 |
| 1998.5–2002 | 5.9L 24V ISB (VP44) | Ram 2500/3500 |
| 2003–2007 | 5.9L ISB (24V Common-Rail) | Ram 2500/3500 |
Industrial/Off-Highway: Used primarily on Tier-1 5.9L B-Series engines; verify by ESN before ordering.
Compatibility Notes:
- Most 6.7L (2007.5+) applications use different front seals (e.g., 4931561 / 3804899). Confirm by VIN/ESN.
- If the crank nose shows wear, consider the Cummins wear-sleeve solution (e.g., 3802820) instead of a bare seal.
Specifications
- Type: Front crankshaft main oil seal (service kit)
- OE Part Number: 3937111
- Supersedes/Cross-Refs (ID): 3904353, 3900709
- Includes: Front crank seal and Cummins installer/depth components
- Quantity Required: 1 per engine (sold individually)
Often Paired With
- Install tool: 3824498 (Cummins front seal installation tool)
- Front cover gasket: 3918673 (’94–’02)
- Balancer bolt kit & RTV: Common add-ons during seal service
What’s In The Box
- (1) Genuine Cummins Front Crankshaft Seal Service Kit (3937111) with installer/depth components
Installation Tips
- Clean the crank snout and front cover bore; inspect for grooves. Use the included installer for correct depth.
- Lightly oil the seal lip; do not distort the garter spring. Follow Cummins torque specs.
- If a groove is present on the crank, use a wear-sleeve kit instead of a bare seal.
FAQ
WILL THIS FIT MY 1989–2007 5.9L CUMMINS RAM?
Yes—3937111 is the OE front crank seal service kit for 1989–2007 5.9L (12V, VP44 24V, and 2003–2007 common-rail). Confirm by VIN/ESN.
DOES THE KIT INCLUDE AN INSTALLER?
Yes—the Cummins service kit includes installer/depth components so the seal seats correctly without damage.
WHAT SHOULD I USE FOR A 6.7L (2007.5+)?
Most 6.7L applications use different seals (e.g., 4931561 or 3804899). Check VIN/ESN to be sure.
WHEN SHOULD I REPLACE THE FRONT MAIN SEAL?
Anytime you see oil at the damper/timing cover area, or when the front cover is off for service.
WHAT IF MY CRANK HAS A GROOVE?
Use a wear-sleeve solution (e.g., 3802820) to restore the sealing surface.
