Product Description
Cummins 3802375 — Genuine Lower Engine Gasket Set for 4BT / QSB
MPN: 3802375 | Also Known As: lower gasket set, bottom-end gasket kit | Related / Earlier Kits (ID): 3802019, 3802266
Seal the bottom-end right the first time. The genuine Cummins 3802375 Lower Engine Gasket Set services the lower portion of B-Series 3.9L 4BT / QSB3.9 engines (and select QSB4.5/B4.5C). Ideal for overhauls, leak repairs, and swap builds. Contents vary by engine build and must be verified by ESN to ensure a perfect match.
Features & Benefits
- OE sealing materials & profiles engineered for B-Series thermal expansion and clamp loads.
- Comprehensive lower-end coverage (oil pan, timing/front cover, water pump interface, and related seals—contents may vary by ESN).
- Fewer comebacks vs. piecing individual gaskets—kit approach ensures interfaces are renewed together.
- Genuine Cummins quality for durability, fluid compatibility, and fit.
Verified Fitment
| Engine/Platform | Notes |
|---|---|
| 4BT / 4B3.9 (B-Series) | Primary target platform. Industrial/off-highway usage; verify by Engine Serial Number (ESN). |
| QSB3.9 | Tier-era QSB3.9 variants (e.g., VP30) — contents/“top-hat” seal style may differ; verify by ESN. |
| QSB4.5 / B4.5C | Seen on select 4.5L B-Series derivatives—ESN verification required. |
Automotive / Swap Notes: 4BT engines were not factory-installed in Ram trucks; this kit is commonly used in swap builds. For 5.9L 6BT/ISB truck engines, use the appropriate 5.9L kit. If you have an early 4BT, you may require earlier kits such as 3802019 or 3802266—check by ESN.
Specifications
- Type: Lower engine gasket set (bottom-end seal kit)
- OE Part Number: 3802375
- Typical Interfaces Covered: Oil pan, timing/front cover, water pump interface, miscellaneous lower seals (actual contents vary by ESN)
- Quantity Required: 1 kit per engine
Often Paired With
- Front & rear main seals (verify by ESN/build option)
- Oil pump pickup tube O-ring and oil pan hardware refresh
- Upper engine (head set) if doing a full rebuild
What’s In The Box
- (1) Genuine Cummins Lower Engine Gasket Set (3802375) — contents per ESN
Installation Tips
- Always verify ESN to ensure kit content compatibility (seal types and counts can change by build).
- Clean all sealing surfaces; avoid over-RTV—use only where Cummins specifies.
- Torque fasteners in sequence to spec; check crank endplay and front cover alignment.
- After first heat cycle, inspect for seepage at oil pan and front cover corners.
FAQ
WILL THIS FIT MY 4BT 3.9L?
Yes—3802375 targets 4BT/4B3.9 lower-end sealing. Because contents vary by build year and seal style, confirm by ESN.
WHAT ABOUT QSB3.9 OR QSB4.5/B4.5C?
Many QSB3.9 and some QSB4.5/B4.5C engines use 3802375, but certain years (e.g., “top-hat” seal era) differ. Verify by ESN before ordering.
DOES THIS KIT FIT 5.9L 6BT/ISB TRUCK ENGINES?
No—this kit is for 3.9L platforms. Use the correct 5.9L kit for 12-valve, VP44, or common-rail engines.
WHAT’S INCLUDED?
Typical lower-end interfaces: oil pan gasket, timing/front cover gaskets, water pump/interface seals, and assorted lower seals. Exact pieces vary by ESN.
ARE THERE EARLIER/ALTERNATE KIT NUMBERS?
Yes—earlier 4BT builds may use 3802019 or 3802266. If your engine is pre-update, those kits may be correct.
