Product Description
Cummins 3802422 — Piston Ring Set (.020" / 0.50 mm) for B-Series 5.9L
MPN: 3802422 | Also Known As: .020" oversize ring set, 0.50 mm OS ring set | Application: Non-Certified 5.9L B-Series (see fitment)
Why This Part
- ✓ OE material & geometry for proper sealing, compression, and oil control.
- ✓ .020" (0.50 mm) oversize for cylinders bored/honed to +0.020".
- ✓ Direct replacement on many 5.9L B-Series builds (verify by ESN and piston groove style).
- ✓ Restores power, emissions, and oil consumption after overhaul.
Quick Specs
| Type | Piston ring set (.020"/0.50 mm oversize) |
|---|---|
| OE Part # | 3802422 |
| Qty Required | 1 set per piston (order 6 for a complete 6-cyl engine) |
| Engine Family | Cummins B-Series 5.9L (see Verified Fitment) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1998 | 5.9L Cummins 6BT (12-Valve) | Ram 2500/3500 |
| 1998.5–2002* | 5.9L Cummins ISB (24-Valve, VP44) | Ram 2500/3500 |
*Compatibility note: Common across 1989–2002 B-Series applications, but always verify by ESN and piston groove style for 24-valve builds.
Industrial / Off-Highway (Common)
Frequent on B-Series equipment engines such as 4B3.9 / 4BT3.9 / 6B5.9 / 6BT5.9 / 6BTA5.9 in Case/Case-IH and other off-highway platforms (confirm by ESN).
Often Paired With
- Other ring sizes: 3802421 (STD) · 3802423 (.040"/1.00 mm)
- Piston kits: 3802561 (STD) and matched oversizes (verify bore)
- Lower engine gasket set: 3802376 (B-Series 5.9L)
- Hone & bearings: finish hone to spec; install new rod/main bearings as required
What’s In The Box
- (1) Cummins piston ring set for a single piston (3802422, .020"/0.50 mm OS)
- Repeat x6 for a complete 6-cylinder engine
Install Tips
- Measure bore, pistons, and ring end gap after final hone; fit per Cummins spec.
- Confirm piston groove width/profile before selecting ring set.
- Stagger ring end gaps; lubricate and use a proper ring compressor.
FAQ
WILL THIS FIT MY 1989–2002 5.9L CUMMINS RAM?Generally yes for many B-Series overhauls—verify by ESN and piston groove style, especially on 1998.5–2002 24-valve engines.
IS THIS SOLD PER CYLINDER OR FOR THE WHOLE ENGINE?Sold per cylinder (1 piston). Order 6 sets for a complete 6-cylinder engine.
WHAT DOES .020" OVER MEAN?The cylinder has been bored/honed to +0.020" (0.50 mm). Use rings that match the piston and finished bore size.
DO I NEED NEW PISTONS?If the pistons are worn or groove widths don’t match the ring profile, replace pistons or choose the correct ring set.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3802422 piston ring set.
