Product Description
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
| Brand / Part # | Interstate-McBee M-3900068 |
|---|---|
| OEM Reference | Cummins 3900068 (Ring Dowel) |
| Diameter | 14 mm |
| Location | Main bearing cap alignment (bottom-end) |
| Material | Steel |
| Cross-Refs | M3900068, 499187 |
| Condition | New – aftermarket replacement |
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
FAQ
Is this the same as Cummins 3900068?Yes. M-3900068 is the Interstate-McBee aftermarket equivalent to Cummins 3900068 ring dowel.
Where is this dowel used?
It’s the main bearing cap alignment dowel in the bottom end on B-Series engines that specify 3900068.
Will it fit both 5.9L and 6.7L?
Yes—common across 1989–2018 5.9L and 6.7L Cummins applications that call for 3900068. Always confirm by ESN.
Is 14 mm the correct size?
Yes—this listing is for the 14 mm dowel used with main cap alignment on the specified engines.
Product Videos
Custom Field
YEAR 1989-2018
MAKE DODGE
ENGINE 5.9L,6.7L
