Cummins Industrial SAE Flywheel & Housing Identification Guide

Cummins Industrial SAE Identification Guide

Technical Specifications for 6BTA, B5.9-C, QSB 5.9/6.7, and Heavy-Duty Cummins Series

Measurement Key (Cross-Section)

SAE Measurement Diagram

How to use this key:

  • XD: Housing Bore Inside Diameter.
  • XB: Housing Bolt Circle Diameter.
  • XE: Flywheel Max Outside Diameter.
  • XF: Flywheel Bolt Circle.
  • XG: The "G" Dimension (Total Offset).
×

📋 Step 1: Pre-Measurement Checklist

1. Housing Bore (XD)Measure the ID of the rear adapter ring.
2. Flywheel OD (XE)Max diameter excluding the ring gear.
3. G-Dimension (XG)Housing face to flywheel mounting face.
4. Crank BoltsCount the bolts on the crank flange (8 or 12).

Looking to purchase an engine or just need to keep up with your measurements, download this worksheet for documenting all of the information you need to identify your flywheel & flywheel housing.

Get Application Sheet
SAE Housing Dimensions (Engine Side)
SAE No. Inside Diameter (XD) Outside Diameter Bolt Circle (XB) Holes
SAE #0 25.500" 28.000" 26.750" 16
SAE #1 20.125" 21.750" 20.875" 12
SAE #2 17.625" 19.250" 18.375" 12
SAE #3 16.125" 17.750" 16.875" 12
SAE Industrial Flywheel Dimensions (Drive Side)
Size Max O.D. (XE) Bolt Circle (XF) G-Dimension (XG) Common Cummins Engine
SAE 14 18.375" 17.250" 1.00" N14, NT855, QSL9
SAE 11.5 13.875" 13.125" 1.56" 6BT, 6BTA, B5.9-C, QSB 5.9, QSB 6.7
SAE 10 12.375" 11.625" 2.12" 4BT, 4BTA, B3.3
SAE 8 10.375" 9.625" 2.44" Auxiliary B-Series
Cummins Crankshaft Flange Reference
Crank Pattern Bolt Circle ID Engine Series Flywheel Hardware
8-Bolt ~2.5" - 3.0" 4BT, 6BT, QSB 5.9/6.7 M12 x 1.25
12-Bolt ~4.0" - 4.5" L10, M11, N14, ISM M14 x 1.5
⚠️ Hardware Warning: Industrial Cummins engines utilize Metric bolts for the flywheel-to-crank connection but often use Standard (UNC) bolts for the housing-to-transmission connection. Check threads before installation.

Can't Identify Your Part?

Provide us with your Cummins Engine Serial Number (ESN) and we will identify the exact SAE components required.


Get Expert Support