Interstate-McBee M-3900068 – 14mm Main Bearing Cap Dowel (1989–2018 5.9L/6.7L Cummins)

The Interstate-McBee M-3900068 is an OEM-style 14mm main bearing cap ring dowel used on Cummins B-Series engines to precisely align the main cap during assembly. It restores factory geometry, prevents cap shift under load, and supports long-term bottom-end durability on 1989–2018 5.9L & 6.7L Cummins.

• Direct-fit alignment: Matches Cummins 3900068 for hassle-free install.
• OEM-equivalent quality: Precision machined for repeatable main cap location.
• Heavy-duty build: Durable steel dowel resists fretting and deformation.
• Aftermarket value: Interstate-McBee performance at a fraction of OEM cost.

Specifications

Vehicle Fitment

Always confirm by engine serial number (ESN) for exact compatibility.

• Dodge Ram 2500/3500 – 5.9L Cummins
  • 1989–1993 12-Valve 6BT
  • 1994–1998 12-Valve 6BT (P-pump)
  • 1998.5–2002 24-Valve ISB
  • 2003–2007 24-Valve ISB (Common-Rail)
• Dodge/Ram 2500/3500 – 6.7L Cummins
  • 2007.5–2018 24-Valve ISB 6.7L
• Other B-Series Applications: Common to 4B/6B/ISB/QSB platforms where 3900068 dowel is specified.

Install Notes

• Inspect the block and cap bores; replace any damaged dowels during main bearing service.
• Seat dowels fully and squarely; verify cap alignment before torqueing main bolts/studs.
• Follow the Cummins service manual for torque specs and sequence.

What’s Included

• (1) Main bearing cap ring dowel, 14 mm

Why Buy From CPP Diesel

• Real diesel tech support to validate ESN-specific fitment
• Fast shipping and easy returns
• Huge B-Series inventory for one-trip checkout

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