Product Description

CUMMINS 3904217 OEM 14MM MAIN BEARING CAP BOLT, genuine Cummins hex head cap screw, M14 x 2.00 x 119, main bearing bolt for 5.9L 12-valve 6BT, 1989-1997 Dodge Ram, B-series bottom end hardware, crankshaft main bearing cap fastener, 4BT 6BT Cummins.

Cummins 3904217 OEM 14mm Main Bearing Cap Bolt – 5.9L 12-Valve (1989–1997)

When you’re rebuilding the bottom end of your 5.9L 12-valve, the Cummins 3904217 OEM 14mm main bearing cap bolt is the only hardware you should trust between your crankshaft and the main caps. This genuine hex head cap screw uses the correct M14 x 2.00 x 119 mm dimensions and factory thread engagement so your main caps clamp exactly like Cummins intended.

Whether you’re refreshing a high-mileage work truck or dialing in a performance 6BT build, sticking with genuine Cummins hardware helps maintain bearing crush, cap alignment, and long-term durability. No guessing on length, no mystery metallurgy—this is the same spec fastener your engine left the factory with.

Sold individually – 14 bolts required per engine.

Key Features

• Genuine Cummins OEM 3904217 hex head cap screw
• 14 mm main bearing cap bolt for B-series bottom ends
• Correct M14 x 2.00 x 119 mm thread and length
• Designed for 1989–1997 Dodge Ram 5.9L 12-valve (6BT) engines
• Maintains factory clamping load and bearing crush
• Compatible with many 4B / 4BT / 6B / 6BT industrial and automotive applications (verify by ESN)
• Sold individually – order 14 for a full set of main cap bolts

Fitment – Cummins 3904217

This OEM main bearing cap bolt is commonly used in:

• 1989–1997 Dodge Ram 2500/3500 with 5.9L 12-valve Cummins (6BT) engines using 14 mm main bolts
• Cummins B-Series 5.9L automotive and industrial engines using 14 mm main cap hardware
• Cummins 4B / 4BT 3.9L engines in select applications (confirm by engine serial number)

Important: Cummins used both 12 mm and 14 mm main bolts on B-Series engines. Always confirm your block’s main bolt diameter and torque spec using the engine serial number (ESN) and a current Cummins service manual before ordering or installing hardware.

Recommended Cummins Companion Parts

Fresh main bolts pair best with new bearings and alignment hardware. CPP Diesel stocks the following genuine Cummins parts that are frequently installed with 3904217:

• CUMMINS 4955855 OEM MAIN BEARING SET (STANDARD) – B-SERIES / RAM 5.9L & 6.7L
• CUMMINS 4938948 OEM CRANKSHAFT THRUST BEARING – 5.9L/6.7L (1989–2018)
• CUMMINS 3900068 OEM RING DOWEL (14MM) – CYLINDER HEAD / MAIN BEARING CAP – 5.9L & 6.7L
• CUMMINS 3927948 OEM 12MM MAIN BEARING CAP BOLT – 5.9L/6.7L (1998.5–2018) (for later 12 mm main bolt applications)

Installation Notes

• Clean threads in the block and on each bolt before installation.
• Lightly oil the threads and under the bolt head with clean engine oil (unless your service manual specifies otherwise).
• Follow the factory torque sequence and multi-step torque values from a current Cummins service manual.
• Do not mix 12 mm and 14 mm hardware on the same engine.
• Inspect old bolts for stretching, corrosion, or thread damage—replace as a full set when in doubt.

FAQ – Cummins 3904217 Main Bearing Cap Bolt

WILL THIS FIT MY 1989–1997 5.9L 12-VALVE CUMMINS?

Yes, this bolt is the correct 14 mm main bearing cap bolt for most 1989–1997 Dodge Ram 2500/3500 trucks equipped with the 5.9L 12-valve Cummins, provided your block uses 14 mm main bolts. Always verify your engine serial number (ESN) and check main bolt diameter before ordering.

HOW MANY 3904217 BOLTS DOES ONE ENGINE REQUIRE?

A standard B-Series 5.9L bottom end uses 14 main bearing cap bolts. This part is sold individually, so most 5.9L engines will require quantity 14 for a complete set. Some industrial or non-standard configurations may differ—count existing bolts during teardown to be sure.

WHAT TORQUE SPEC SHOULD I USE FOR THESE MAIN CAP BOLTS?

Torque specs can vary by engine family, block casting, and revision. Many Cummins B-Series engines use a three-step torque procedure for main bearing cap bolts, but you should always follow the latest Cummins service manual for your specific ESN. Do not rely solely on generic torque charts when assembling an engine.

CAN I MIX OEM MAIN BOLTS WITH AFTERMARKET MAIN STUDS?

No. If you upgrade to an aftermarket main stud kit, you should run that system on all main caps and follow the stud manufacturer’s instructions. Use Cummins 3904217 OEM bolts when you want to retain factory-style main cap hardware and torque procedures.

DOES THIS BOLT ALSO FIT 4BT OR INDUSTRIAL B-SERIES ENGINES?

The 3904217 bolt is widely used on 4B / 4BT / 6B / 6BT engines in industrial and off-highway applications. However, there are exceptions, so always cross-check your ESN and parts manual to confirm this is the correct main bolt for your specific engine.

Specifications for cummins 3904217