Interstate-McBee M-3900629 Hexagon Flange Head Cap Screw – 97.5–02 5.9L Cummins (Tappet Cover Bolt)

OEM-style hex flange head cap screw for the B-Series 5.9L Cummins. Commonly used as the tappet (cam follower) cover bolt on late 2nd-gen applications. Built to OEM dimensions for reliable clamping and leak-free sealing when paired with the correct gasket and grommets.

• Direct OEM cross-reference: Cummins 3900629 (tappet cover bolt).
• Application-proven: Primary fitment for 1998.5–2002 5.9L Cummins 24-valve (verify by ESN).
• Correct hardware spec: M8 x 1.25 x 16 mm hex flange head cap screw.
• Aftermarket value: Interstate-McBee quality at a better price than OEM boxed hardware.
• Quantity note: Tappet cover typically uses 6 bolts total.

Specifications

Vehicle Fitment

Always verify by engine serial number (ESN), build date, and cover design.

• Dodge Ram 2500/3500 with 5.9L Cummins
  • 1998.5–2002 24-Valve ISB – primary OEM listing for 3900629.
  • 1997.5–1998 12-Valve – some builds may differ; confirm hardware before ordering.
• Also seen on B-Series variants (4BT/6BT) depending on cover/housing configuration.

Related Service Parts

• Tappet Cover Gasket – Cummins 3284623 (1989–2002 coverage varies by engine).
• Tappet Cover Grommet – Cummins 3928759 (1998.5–2002), 3900267 (1989–1998).

Install Notes

• Clean threads and mating surfaces. Replace gasket and grommets when resealing the tappet cover.
• Tighten in a cross-pattern; follow the Cummins service manual for torque specs.

Warranty

Interstate-McBee new parts carry manufacturer warranty coverage against defects in materials and workmanship. Contact us for specific terms for fasteners.

Why Buy From CPP Diesel

• ESN-verified fitment help from real diesel techs.
• Fast shipping, easy returns, and curated B-Series parts.
• Bundle with gasket and grommet to finish the job right.

FAQ