Product Description
Cummins 5273412 — Genuine Crankshaft Drive Gear for ISB 5.9L & 6.7L
MPN: 5273412 | Also Known As: crankshaft gear, timing gear, crank gear | Cross-Refs (ID only): Cummins 3949357, 3965389 · Mopar 5086726AB
Genuine Cummins crankshaft drive gear that maintains precise timing between the crankshaft and cam gear on ISB platforms. Direct-fit for 2003–2018 Ram 5.9L/6.7L common-rail and widely used on ISB/QSB industrial applications (verify by ESN). Sold individually (1 per engine).
Features & Benefits
- OE tooth profile & hardness for quiet operation and long service life.
- Correct press-fit design to prevent timing slip under load.
- 36-tooth spur gear for accurate synchronization with the cam gear.
- Drop-in OEM replacement that matches factory timing marks.
- Backed by Cummins for fit, function, and durability.
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 2003–2007 | Ram 5.9L ISB (24V Common-Rail) | Ram 2500/3500 |
| 2007.5–2018 | Ram 6.7L ISB (24V Common-Rail) | Ram 2500/3500 |
Industrial/Off-Highway: ISB/QSB 4.5/5.9/6.7 (EPA13+ usage noted by Cummins for ISB/QSB 6.7). Always verify by ESN before ordering.
Compatibility Notes:
- Mopar 5086726AB is the Chrysler/Ram number that cross-references to Cummins 5273412 for 2003–2018 Ram 5.9/6.7.
- Cummins Shop indicates this gear is used primarily on **EPA13** 6.7L ISB/QSB engines; for late-model or industrial equipment, confirm by ESN.
- When replacing a damaged gear, inspect the cam gear and woodruff key, and re-time per Cummins procedures.
Specifications
- Type: Crankshaft timing gear (spur)
- Tooth Count: 36
- OE Part Number: 5273412
- Cross-References (ID): 3949357, 3965389, Mopar 5086726AB
- Quantity Required: 1 per engine (sold individually)
Often Paired With
- Front crankshaft seal & timing cover gasket (year-specific)
- Woodruff key (inspect/replace if worn)
- Fresh engine oil & filter after repair if debris was present
What’s In The Box
- (1) Genuine Cummins Crankshaft Drive Gear (5273412)
Installation Tips
- Use an appropriate bearing separator/gear puller to remove the old gear; clean the crank snout thoroughly.
- For installation, use thermal expansion (heat gear/cool crank) and align timing marks; ensure the gear seats fully against the crank shoulder.
- Verify gear seating with a feeler gauge and re-check crank/cam timing marks before reassembly.
FAQ
WILL THIS FIT MY 2003–2018 RAM 5.9L/6.7L?
Yes—this is the OE-style crankshaft gear for 2003–2018 Ram 5.9L and 6.7L common-rail applications (confirm by VIN/ESN).
WHAT ARE THE COMMON CROSS-REFERENCES?
Cummins 3949357 & 3965389 and Mopar 5086726AB are typical identifiers that cross-reference to 5273412.
HOW MANY TEETH DOES THIS GEAR HAVE?
36 teeth (spur gear).
DO I NEED SPECIAL TOOLS?
A heavy-duty bearing separator/gear puller is recommended for removal. For installation, follow Cummins procedures; thermal expansion methods are commonly used to press-fit the gear.
IS THIS A GENUINE CUMMINS PART?
Yes—this is an OEM Cummins crankshaft drive gear for proper fit and durability.
