Cognito CV Front Driveline Kit 7-9"/10-12" Lift | 2017-2019 Silverado/Sierra 2500HD/3500HD Duramax

⚠️ 1350 U-Joint at Front Differential Required: This driveline is only compatible with trucks originally equipped with a 1350 U-joint at the front differential. Trucks with a different factory U-joint size at the front differential are not compatible. Verify your factory front differential U-joint size before ordering.

⚠️ Six-Speed Allison Transmission — Additional Part Required: If your truck is equipped with the six-speed Allison transmission, the Cognito Shift Linkage Relocation Bracket (Part Number 110-90278) is required and is not included in this kit. Contact the OFAS team to add it to your order before shipping.

The Obsidian Vision

At 7 to 12 inches of front lift on the 2017–2019 K2 Silverado and Sierra 2500HD/3500HD Duramax, the factory front driveline U-joint operating angles are well beyond the safe threshold for any 4WD operation — producing severe vibration, rapid U-joint failure, and potential driveline separation. The Cognito CV Front Driveline Kit covers both the 7–9-inch and 10–12-inch lift ranges in a single direct bolt-in kit: a 1310 series double cardan CV joint at the transfer case end, a 1330 U-joint at the differential end, and the Cognito Allison Transmission Bracket included. Complete bolt-in replacement, made in the USA, 30-minute install, engineered specifically for the K2 2500HD/3500HD Duramax platform.

Concierge Fitment Guarantee

Every order is manually reviewed by our technicians to ensure 100% compatibility with your build before we ship.

Engineering Breakdown

• Eliminates the severe U-joint operating angle overload generated by 7–12 inches of front lift on the 2017–2019 K2 Silverado/Sierra 2500HD/3500HD Duramax platform — at these lift heights, the factory straight U-joint front driveline cannot operate in 4WD without producing vibration, accelerated joint destruction, and risk of driveline separation. This kit covers both the 7–9-inch and 10–12-inch lift ranges in a single SKU.
• Corrects the transfer case end driveline angle through a 1310 series double cardan CV joint — a constant velocity joint design that splits the operating angle equally across two U-joints phased 180 degrees apart, canceling the velocity variation that a single U-joint produces at high operating angles and delivering smooth, vibration-free power transfer at 7–12 inches of front lift on the K2 Duramax platform.
• Delivers a complete bolt-in driveline kit with a 1330 U-joint at the differential end and the Cognito Allison Transmission Bracket included — the transmission bracket accommodates the driveline geometry change at the Allison transmission output, providing a complete, no-fabrication installation solution for the 2017–2019 K2 2500HD/3500HD Duramax with six-speed or other Allison transmission configurations.

This driveline covers Cognito 7–9-inch and 10–12-inch lift applications on the 2017–2019 K2 2500HD/3500HD Duramax platform in a single SKU. The 1310 series double cardan CV joint at the transfer case end is the critical component that allows smooth 4WD operation at these lift heights. The 1330 U-joint at the differential end provides the heavy-duty joint interface at the front differential flange — compatible with trucks originally equipped with a 1350 U-joint at the front differential only. The Cognito Allison Transmission Bracket is included. If your truck has the six-speed Allison transmission, the Shift Linkage Relocation Bracket (SKU 110-90278) is also required and must be ordered separately. Made in the USA. At 22 lbs, this ships standard parcel.

Audit Table

Verified Fitment (OFAS Standard)

✅ CONFIRMED — Chevrolet Silverado 2500HD (K2, 2017–2019) — Duramax; 1350 U-Joint at Front Diff:
2017–2019 Chevrolet Silverado 2500HD WT, LT, LTZ, High Country 4WD
2017–2018 Chevrolet Silverado 2500HD Base, LS 4WD
2017 Chevrolet Silverado 2500HD Base 4WD

✅ CONFIRMED — Chevrolet Silverado 3500HD (K2, 2017–2019) — Duramax; 1350 U-Joint at Front Diff:
2017–2019 Chevrolet Silverado 3500HD WT, LT, LTZ, High Country 4WD SRW & DRW
2017–2018 Chevrolet Silverado 3500HD Base 4WD SRW & DRW

✅ CONFIRMED — GMC Sierra 2500HD (K2, 2017–2019) — Duramax; 1350 U-Joint at Front Diff:
2017–2019 GMC Sierra 2500HD Base, SLE, SLT, Denali 4WD

✅ CONFIRMED — GMC Sierra 3500HD (K2, 2017–2019) — Duramax; 1350 U-Joint at Front Diff:
2017–019 GMC Sierra 3500HD Base, SLE, SLT, Denali 4WD SRW & DRW

❌ REQUIREMENTS & CRITICAL NOTICES:
⚠️ 1350 U-JOINT AT FRONT DIFFERENTIAL REQUIRED: Compatible only with trucks originally equipped with a 1350 U-joint at the front differential. Trucks with a different factory U-joint size at the front differential are not compatible with this driveline. Verify your factory front differential U-joint size before ordering — contact the OFAS team if you are unsure.
⚠️ SIX-SPEED ALLISON — SHIFT LINKAGE RELOCATION BRACKET REQUIRED (SKU 110-90278): If your truck is equipped with the six-speed Allison transmission, the Cognito Shift Linkage Relocation Bracket (Part Number 110-90278) is required and is not included in this kit. Contact the OFAS team to add it to your order before shipping.
⚠️ 4WD MODELS ONLY: This driveline is for 4WD models only. 2WD 2500HD/3500HD trucks do not have a front driveline and do not require this part.
⚠️ K2 GENERATION ONLY (2017–2019): Engineered for the K2 generation Silverado/Sierra 2500HD/3500HD Duramax only. Not compatible with the T1 generation (2020–2026) — see SKU 210-90983 for T1 2020–2023 Duramax applications.
Install before operating the vehicle in 4WD after lift kit installation. Do not operate in 4WD with the factory driveline installed at 7–12 inches of front lift.

Installation & Technical Notes

Estimated Install Time: 30-minute DIY install — direct bolt-in replacement with standard hand tools and a torque wrench.
Six-Speed Allison: If equipped with the six-speed Allison transmission, install the Shift Linkage Relocation Bracket (SKU 110-90278) before or during driveline installation. Do not install the CV driveline without the shift linkage bracket on six-speed Allison-equipped trucks.
Allison Transmission Bracket: The Cognito Allison Transmission Bracket is included in this kit. Install per Cognito's included instruction sheet.
1350 U-Joint Verification: Confirm the factory front differential U-joint is a 1350 series before installation. If the factory U-joint is a different size, this driveline is not compatible.
Driveline Phasing: Verify driveline phasing is correct after installation — incorrect phasing will produce vibration at speed. Refer to Cognito's included instruction sheet for phasing verification procedure.
Torque Specifications: Torque all driveline mounting fasteners to GM specification. Refer to Cognito's included instruction sheet for all torque values.
Re-Torque Interval: Re-torque all driveline fasteners after the first 500 miles of driving post-installation.

Wheel & Tire Fitment

This is a driveline component and does not affect wheel offset, tire clearance, or suspension lift height. Wheel and tire fitment is determined by your installed Cognito lift kit configuration. Contact the OFAS team to confirm your complete 4WD supporting modification list for your specific lift height and truck configuration.

Our team is standing by to verify your factory front differential U-joint size, Allison transmission variant, and Cognito lift height before you order — the 1350 U-joint and six-speed Allison requirements are the two most critical checks on this kit. Purchase with confidence; we review every build.