Commercial Vehicle Output Flanges: High-Torque Transmission Sourcing Guide

When casting numbers or OEM decals are obliterated by oil and road debris, accurate identification requires measuring four critical mechanical dimensions:

1. Internal Spline Geometry: Measure exact tooth count, major diameter (crest-to-crest), minor diameter (root-to-root), and the tooth pitch profile (involute vs. straight parallel spline, such as DIN 5480 standard).

2. Flange Mating Interface: Determine whether the face is a flat friction pilot pattern (SAE standard 1710/1810) or a mechanical intermeshing cross-tooth face (DIN KV 100, 120, 150, or 180 mm outer diameter with 70° or 86° tooth angle).

3. Oil Seal Neck Collar: The outer ground diameter where the transmission or differential radial oil seal seats, plus total collar insertion depth.

4. Bolt Circle Diameter (PCD) & Hole Count: Pitch diameter, bolt hole clearance diameter, or thread pitch. Our Bursa export desk cross-checks these parameters against our technical database to identify the precise OEM replacement code.

Heavy commercial vehicles subject transmission and pinion flanges to severe reverse shock loads, especially during downshifts, retarder braking, and high-load acceleration. Standard cast iron or low-carbon steel components will fracture along the spline root due to notch sensitivity.

KNB Automotive strictly supplies flanges manufactured from closed-die forged chromium-molybdenum alloy steel (42CrMo4 / 4140) or case-hardening steel (20CrMnTi). The internal splines and seal journals undergo controlled induction hardening to 58–62 HRC to a depth of 1.8 to 2.5 mm, while maintaining a ductile, shock-absorbing core (28–32 HRC) to absorb torsional peak spikes without brittle rupture.

Traditional SAE companion flanges transfer rotational torque through surface friction generated by heavy bolt clamping force. Under extreme high torque (exceeding 25,000 Nm on Class 8 long-haul rigs), friction slippage can occur, placing high shear stress directly onto the driveshaft bolts and resulting in bolt stretching, vibration, and catastrophic separation.

Cross-tooth serrated flanges (DIN 0015 / ISO 12667 KV type) feature precision intermeshing 70° or 86° teeth across the entire face. Torque is transmitted by direct mechanical positive engagement rather than friction. This design eliminates shear forces on the fasteners, allows a smaller overall flange diameter, cuts rotating weight, and delivers 35–45% higher torque capacity with zero risk of rotational bolt loosening.

Yes. Many fleet operators run mixed fleets or specialized vocational vehicles with obsolete OEM gearboxes (Eaton twin countershaft, legacy ZF Ecosplit, Allison legacy, or custom retarder integrations). Leveraging Bursa’s versatile automotive engineering infrastructure, we evaluate custom sourcing requirements using 2D CAD engineering prints, physical worn master samples, or 3D STEP files.

We manage tooling creation, forging dies, CNC spline broaching, precision surface grinding, and dynamic balancing for low-to-medium batch runs that major OEM parts channels typically refuse to quote.

Every commercial consignment exported by KNB Automotive is supported by comprehensive foreign trade compliance documents to ensure swift customs clearance:

• Customs Documentation: Commercial Invoice, Packing List, and Chamber of Commerce validated Certificate of Origin.

• A.TR Movement Certificate: Under the European Union–Türkiye Customs Union, industrial parts originating in Türkiye qualify for duty-free entry into all 27 EU member countries.

• EUR.1 Certification: Available for qualifying destinations having bilateral preferential trade pacts with Türkiye.

• Quality Inspection Reports: Material composition certificates (EN 10204 3.1), hardness inspection sheets, and balance runout records upon contract request.

Output flanges represent high-density, relatively compact metallic freight. Sourcing flanges alone in small batches results in disproportionate air or LCL pallet shipping costs per unit. KNB Automotive specializes in multi-category shipment consolidation from Bursa.

We allow international distributors to consolidate heavy transmission output flanges on the same pallet or container with commercial vehicle flywheels, clutch servo units, wheel hubs, brake discs, air dryer valves, and lighting kits. This slashes per-unit import logistics overhead by up to 30% and centralizes customs clearance under a single commercial invoice.