Steering - bump steer after a lift

The 4x4Wire JK recently underwent a slight transformation - from stock to gears, lockers, and lift. That change included new (larger) tires. But, that change did not include replacing the steering damper. Extended road driving pointed out the need to upgrade the steering damper in order to reduce vibration caused by the larger tires on certain sections of road.

Upgrade your Wrangler with a Jeep lift kit from ExtremeTerrain

The ultimate is the high-steer mod that includes a new style shock from Fox. That mod does require change of the mounting bracket and tie rod ends. And, the kit has undergone 2-3 design changes. As it stands, all necessary pieces and parts are not available, back-order until December. And, the key component, the Fox shock, is not shipping until mid-February 2013.

I will try a KBY shock and upgrade to the the new high-steer kit when parts are available.

The pictures display the Synergy Suspension (http://synergysuspension.com) Jeep JK Steering Correction Kit. The first image is the stock configuration.

Comments 6

John Stewart on Saturday, 10 November 2012 18:44

Steering update

After driving around with the "heavy-duty" damper (or stabilizer), it is slightly better than stock. However, road sections with numerous patches and rough surfaces create a vibration in the front end.

0 Reply

John Stewart on Monday, 19 November 2012 00:10

After completing about a 1000 mile trip on California freeways and secondary roads in varying degrees of disrepair, I find the heavy duty steering damper does perform better than the stock. However, I do experience a wobble where the tires control the steering wheel in the 40-50 mph range. That is consistent on all types of road surfaces, whether accelerating or decelerating.

I will be installing the high-steer option and will have an opportunity to test drive prior to installing the final Fox shock.

John Stewart on Thursday, 29 November 2012 22:30

Synergy Suspension Jeep JK High Steer Kit

The Synergy Suspension (http://synergysuspension.com) Jeep JK steering correction kit is now installed. The kit does provide a significant improvement in steering and handling for the Jeep JK after a lift. Currently, I am still running with the KYB Steering Dampener as the desired Fox component will not be available until February 2013. Overall, great performance improvement.

My personal recommendation is that anytime a lift is considered, part of the installation should be a high-steer correction kit.

A couple of notes...

1. The drag link is the same for a lift from 3.5 inches to 7 inches. However, the idea use is for a lift somewhere between. In my case, a 3.5 inch lift, there was a slight modification (cutting off about 1/4 inch) was required.

2. A balancing of tires and alignment of front end is required. If the shop you use does not have a special alignment rack, insist that a complete, professional front-end alignment be accomplished.

3. When tires are balanced, positioning of the weights and the difference between steel and lead weights becomes apparent. Often, more steel weights are necessary to properly balance a tire. However, often a simple re-alignment of the tire on the rim will shift natural heavy spots enough to reduce the need for excessive wheel weights.

My personal recommendation is that anytime a lift is considered, part of the installation should be a high-steer correction kit.

A couple of notes...

1.  The drag link is the same for a lift from 3.5 inches to 7 inches.  However, the idea use is for a lift somewhere between.  In my case, a 3.5 inch lift, there was a slight modification (cutting off about 1/4 inch) was required.

2.  A balancing of tires and alignment of front end is required.  If the shop you use does not have a special alignment rack, insist that a complete, professional front-end alignment be accomplished.

3.  When tires are balanced, positioning of the weights and the difference between steel and lead weights becomes apparent.  Often, more steel weights are necessary to properly balance a tire.  However, often a simple re-alignment of the tire on the rim will shift natural heavy spots enough to reduce the need for excessive wheel weights.

Cancel Update Comment

Jerry Smith on Friday, 30 November 2012 19:49

It sounds like you have overlooked a very important step with your lift

ANY time you add 3" or more lift to a Wrangler TJ or JK, you better get it aligned. Even more than that, you need to know that new specs apply to a Wrangler lifted this much. Stock specs for your JK are +3.2 to +5.2 degrees. With the lift, you need to drop back to about +2.5 to +3 degrees to compensate for the lift, the driveline angle, and the larger tires.

John Stewart on Friday, 30 November 2012 23:57

RE:It sounds like you have overlooked a very important step with your lift

Actually, I did get it aligned. My point was to make sure that other people do take the step and get their front end aligned after a lift. And, that alignment should be accomplished by a shop that does have the special alignment rack and trained techs.

Steering is a critical part of vehicle performance and often overlooked.

John Stewart on Monday, 03 December 2012 14:47

Steering Update

Synergy High Steer is installed and front end aligned. While that mod works as advertised, another "gotcha" has surfaced. Seems the yaw sensor for the JK is not happy with stiff sidewall tires and a lift. This is noted when you are in a sharp turn at speed (curved freeway entrance ramp). With the lack of sidewall flex, the yaw sensor will automatically apply the brake and reduce speed. It is a strange and unforgettable feeling.

Luckily, there is a cheap and easy fix -- tire pressure.

My tires are Load Range C. Those tires seem to need less than 35 pounds air pressure in the tire.

Higher load range tires require less tire air pressure. For example, my alignment shop (Roger Daniel's Brake and Alignment, Santee, CA) has found than Load Range G tires require tire air pressure in the 28 pound range.