Product Description
Cummins 3920706 — Expansion Plug (Turbo Drain / Core Plug)
MPN: 3920706 | Also Known As: expansion plug, freeze plug, core plug, turbo drain plug | Use Case: seals machined casting/core holes or turbo oil drain provisions (application-specific)
Why This Part
- ✓ OE plug designed for proper sealing in Cummins B-series castings.
- ✓ Direct-fit for many 5.9L & 6.7L applications (verify by ESN/diagram).
- ✓ Corrosion-resistant construction for long service life.
- ✓ Helps prevent coolant or oil leaks from unused ports/casting holes.
Quick Specs
| Type | Cup-style expansion (core/freeze) plug |
|---|---|
| OE Part # | 3920706 |
| Quantity | Sold individually (order the quantity required for your engine location) |
| Install | Press-fit; follow Cummins service procedure and sealant guidance per location |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1998 | Ram 5.9L B-Series (12V) | Ram 2500/3500 (where used) |
| 1998.5–2002 | Ram 5.9L ISB (24V VP44) | Ram 2500/3500 (where used) |
| 2003–2007 | Ram 5.9L ISB (24V Common-Rail) | Ram 2500/3500 (turbo drain/core plug) |
| 2007.5–2018 | Ram 6.7L ISB (24V Common-Rail) | Ram 2500/3500 (turbo drain/core plug) |
Notes: Cummins confirms 3920706 is used primarily on BS3 5.9L B-series; many sellers list Ram coverage from 1989–2018. Exact usage varies by engine casting and location—verify by ESN and service manual.
Often Paired With
- Turbo oil drain hardware/seals (application-specific; verify by ESN/diagram)
- Coolant & oil leak-check supplies after service
- OEM sealant where specified by Cummins for expansion plugs
What’s In The Box
- (1) Genuine Cummins Expansion Plug (3920706)
Install Tips
- Clean bore, inspect for corrosion; align squarely and drive to the specified depth.
- Use sealant only if specified for that location; do not over-peen or distort the cup.
- Pressure-test the system (coolant or oil, as applicable) after installation.
FAQ
WILL THIS FIT MY 1989–2018 CUMMINS RAM?Commonly used across many 5.9L and 6.7L applications, but usage is location-specific. Confirm by ESN and an exploded diagram for your engine.
WHAT DOES THIS PLUG DO?It seals machined casting/core holes or an unused turbo oil drain provision to prevent fluid leaks.
DO I NEED SEALANT DURING INSTALL?Follow the Cummins procedure for your engine location. Some positions call for a light sealant; others install dry.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3920706.
HOW MANY DO I NEED?Sold individually. Quantity depends on how many locations you’re servicing.
