Overview
The TeraFlex 4391000 is a complete high steer system for the Jeep Wrangler JK. It includes high steer knuckles, an HD tie rod and a flipped HD drag link, and it is built for JK vehicles with 4 to 6 inches of lift. It fits 2007 to 2016 Wrangler JK models, including Rubicon, Sahara, Sport and Unlimited trims.
The cast ductile iron high steer knuckles add over 1-1/8 inch of tie rod ground clearance, which reduces tie rod damage and bending. The 1.6 inch O.D. 4140 heat treated chromoly tie rod is over 200% stronger than the factory tie rod, and the drag link is 50% stronger than the factory drag link.
Key features
- High steer knuckles cast from heavy duty ductile iron, one driver and one passenger
- 1.6 inch O.D. 4140 heat treated chromoly HD tie rod
- HD flipped drag link that bolts directly to the high steer knuckle
- Frame side trackbar drop bracket and frame brace kit
- Tie rod end with 4140 chrome moly ball and stud, adjustable preload and 14 degrees of movement
Choosing high steer geometry
High steer geometry moves the tie rod ahead of the axle, which changes the angles the steering linkage works through. A raised knuckle and a flipped drag link help the tie rod clear the axle and frame, but every change to steering geometry also changes how the front wheels track under load. Buyers usually weigh how much lift they run, how much articulation they want and whether the vehicle sees mostly trail work or daily driving.
Steering parts are often replaced together. A track bar that is worn or set for the old geometry can make a high steer swap feel loose, so inspect it along with the tie rod ends, drag link ends and knuckle bushings. Check the bracket welds at each service interval and look for grease leakage, cracked boots and play in the joints.
- Inspect tie rod and drag link ends for play
- Check track bar and frame brace mounts
- Re-check bolts after the first trail runs
Specifications
| Brand | TeraFlex |
|---|---|
| Part number | 4391000 |
| UPC | 843885037842 |
| Lift range | 4 to 6 inch |
| Knuckles | Cast heavy duty ductile iron |
| Tie rod | 1.6 inch O.D. 4140 heat treated chromoly |
| Tie rod end | 4140 chrome moly ball and stud, 1045 carbon steel housing |
| Drag link | 50% stronger than factory, per TeraFlex |
| Ground clearance gain | Over 1-1/8 inch at the tie rod |
| Articulation | 14 degrees of movement |
| Minimum wheels | 17 inch diameter, no more than 5 inch backspacing |
| Installation | Welding required |
Vehicle fitment
It fits 2007 to 2016 Jeep Wrangler (JK) models, including the 70th and 75th Anniversary, Rubicon, Sahara, Sport, Sport S and X trims, plus Unlimited versions of those trims.
The fit range ends at 2016, so 2017 and 2018 JK models fall outside it. Wrangler JL and Gladiator models are not covered. Confirm your vehicle’s year, model and trim before buying.
Installation notes
TeraFlex says installation does not require cutting or removing factory brackets, but welding is required. Wheel alignment is normally needed after a change this large, and welding should be done by someone experienced with frame work.
What’s included
One driver high steer knuckle, one passenger high steer knuckle, HD tie rod, HD flipped drag link, front trackbar drop bracket and frame brace kit.
Not included: a suspension lift in the 4 to 6 inch range, which the kit is designed to work with.
