6-Inch Lift Kit for Steel-Arm GMC Sierra 1500 Denali 4WD
- Requires factory cast steel knuckles or control arms and Magnetic Ride Control
- Fits 2014–2018 GMC Sierra 1500 Denali and 2017–2018 Sierra Denali, 4WD only
- 33-inch tires run on the factory 20-inch wheels
- Cutting and drilling required; 18-inch or larger wheels, mass damper removal if equipped
- High-clearance crossmember and fabricated rear blocks in the kit
The Trail Fortress check
Will it fit your truck?
✓ Fits
Requires cutting and drilling. If wider than 33x12.50 tires are used offset wheels will be required and trimming may be required. 18-inch or larger wheels are required. Please view installation instructions for complete information on proper tire/wheel combinations. If truck is equipped with a mass damper on the front differential the damper must be removed. ONLY fits models with factory cast steel knuckles or control arms. ONLY fits GMC Denali models with Magnetic Ride Control. Fitment on this page is based on the manufacturer’s application data.
About this kit
6-Inch Lift Kit, fitment-checked
Rough Country 18400 delivers 6 inches of lift on 2014–2018 GMC Sierra 1500 Denali and 2017–2018 Sierra Denali 4WD trucks that came with factory cast steel knuckles or control arms. Magnetic Ride Control Denali models are the target application. Cutting and drilling are required, and 33-inch tires clear on the factory 20-inch wheels.
A steel control arm knuckle, the 6-inch front component set, a crossmember box, and fabricated rear blocks make up the kit. It applies to 4WD GMC Sierra 1500 Denali from 2014–2018 and Sierra Denali from 2017–2018 with Magnetic Ride Control. Check the control arm material first — this one is only for cast steel. Cutting and drilling are required, 18-inch or larger wheels are mandatory, tires wider than 33x12.50 need offset wheels and possibly trimming, and a mass damper on the front differential must be removed. Shipping weight: 171 lb.
What’s in the box
Kit contents
- 1× 6" Kit Box 227BOX1
- 1× Crossmember Box 229BOX2
- 1× Steel Control Arm Knuckle 1237BOX1
- 1× 6in Kit FR Components 236BOX2
- 1× 5in Kit Box 188BOX9
Rough Country shares subassemblies across kits, so individual package labels can carry broader application ranges. The complete 18400 kit fits the vehicles shown in the fitment section above.
Specifications
Specs
| Brand | Rough Country |
| Part number | 18400 |
| UPC / GTIN | 00843030173319 |
| Lift height | 6 in |
| Shipping weight | 171 lb |
| Country of origin | US |
| Category | Suspension & Lift Kits › Lift Kits |
| Installation guide | Downloadable PDF |
Why buy here