Product Description
Cummins 3940059 — Camshaft Bushing (Thick) for Storm Block & Common-Rail 5.9L/6.7L
MPN: 3940059 | Also Known As: camshaft bushing, cam bearing, front cam bushing | Cross-Refs: 4983253, PAI 151528, Interstate-McBee M-3940059
Why This Part
- ✓ OE-spec “thick” bushing for late 12V storm block and all common-rail ISB applications.
- ✓ Restores cam support & oil control to reduce wear and noise.
- ✓ Direct-fit front cam bore bushing; press-in with proper alignment to the oil feed.
- ✓ Durable bearing alloy for long service life.
Quick Specs
| Type | Camshaft bushing (thick style) |
|---|---|
| OE Part # | 3940059 (cross: 4983253, PAI 151528) |
| Position | Front cam bore (press-fit) |
| Qty Required | 1 per engine (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1997.5–2002 | Ram 5.9L 24V (VP44) | Ram 2500/3500 |
| 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: Common on ISB/QSB 4.5–6.7 and B-Series 4BT/6BT applications — confirm by ESN.
Fitment note: Earlier 12V (1989–1997) typically uses 3901306 (thin). Storm block 1997.5-up and all CR use 3940059 (thick).
Often Paired With
- Camshaft: OE/aftermarket cam (inspect lobes & journals)
- Tappets/Lifters: Cummins 3947759 (ISB/QSB)
- Front cam bushing (1989–1997 12V): 3901306
- Assembly lube & installer tool for proper press-fit & alignment
What’s In The Box
- (1) Genuine Cummins Camshaft Bushing (3940059)
Install Tips
- Use a proper driver; align the oil feed hole exactly to the gallery.
- Measure cam & bore; verify clearance per service manual.
- Pre-lube bearing surface; rotate cam by hand to confirm smoothness.
FAQ
WILL THIS FIT MY RAM 5.9L/6.7L?Yes — it’s the thick front cam bushing used on 1997.5–2002 24V, 2003–2007 5.9L CR, and 2007.5–2018 6.7L CR (verify by VIN/ESN).
WHAT’S THE DIFFERENCE BETWEEN THICK AND THIN BUSHINGS?Early 12V engines (’89–’97) use a thinner front bushing. Late 12V storm block (’97.5-up) and all CR engines use this thicker 3940059 bushing.
HOW MANY DO I NEED?One per engine (front cam bore). Replace if worn or when rebuilding.
IS THIS A GENUINE CUMMINS PART?Yes — OE Cummins 3940059 with correct geometry and oil feed alignment.
DO I NEED SPECIAL TOOLS?A dedicated bushing installer/driver is strongly recommended to avoid bore damage and to align the oil hole precisely.
