Tierod, Draglink, Trackbar Brace, & Steering Damper

[roaniecowpony]

When you say steering knuckles are you referring to the tie rod ends only or all of the knuckles drag link control arm etc......

The "knuckle" is the part that attaches to the axle housing at the ball joints, and holds the hub, brake disk etc.. It's the part that allows the wheels to steer. On a JL, it's an aluminum forging. But earlier Jeeps were cast iron.

Sponsored

 

[roaniecowpony]

Now that I’m looking a little closer at your pics, you still have the stock suspension on, correct?

Yes. Steersmarts tech rep didn't think their damper would fit with the attenuator in there and stock height, low mount draglink. He suggested exploring a Fox. I'm either going to ditch the attenuator or see if I can find a small diameter damper.

 

[roaniecowpony]

After doing some conservative calculations, I think I'm going to locate the steering damper back to the OEM position. To do that, I need to attach to the tierod in a manner similar to the OEM tierod, which is drilled thru the forged tierod end and a bracket is bolted on. After some measurements, it turns out the Yeti tierod end has a flattened section that is wider than the OEM part by .300". Some quick calculations tell me that the Yeti part can be drilled like the factory part and retain approx 50% more strength than the factory part and will support about 80% (~10k lbs) of the buckling strength of the Yeti 1 5/8" tierod tube. Looks like way overkill in strength, even with drilling the holes in the forged Yeti tierod end. I can use the OEM damper bracket from the OEM tierod.

 

[Rubi-Zero]

Its your Jeep and tie rod to drill, but if it were me, I would fabricate a drop bracket on the trackbar side for the Falcon stabilizer to mount below or even almost parallel to the tie rod. I think this would be simple to fabricate and would be better solution than drilling the steersmart tierod.

 

[roaniecowpony]

Its your Jeep and tie rod to drill, but if it were me, I would fabricate a drop bracket on the trackbar side for the Falcon stabilizer to mount below or even almost parallel to the tie rod. I think this would be simple to fabricate and would be better solution than drilling the steersmart tierod.

I appreciate the suggestion. However, after doing a rough analysis, the loss of bending strength in the tie rod end is negligible in overall buckling strength of the assembly. I set it up in a mill and drilled it I'm putting the damper in the oem location. I'm sure I'll get flamed by the backyard engineers.

 

[roaniecowpony]

Done. Drove it. No issues.

 

[df007]

Drove it on the freeway early this morning. It drove like a $50,000 SUV of the year jeep should drive. One hand at 80 mph, no shimmy on overpasses, no sawing on the wheel, no friggin slop in the steering, Most of all: no "it's a jeep thing". ...and I don't have any steering damper installed, nor do I have 6 or 8 degrees of caster. Hell, I didn't even push in my fuses.

Nice work. So after all that do you think the gearbox adjustment was the biggest improvement?

 

[roaniecowpony]

Nice work. So after all that do you think the gearbox adjustment was the biggest improvement?

df007,
On my JLUR built in Oct 2018, the single biggest improvement was the Steersmarts Yeti Pro trackbar. Steering was spongy like it was hooked with bungy cords to the wheels. The Yeti trackbar took almost all of that out. All that was left was a 1/2-1" bit of dead zone in the steering. The steering box adjustment took that last bit out.

 

[roaniecowpony]

It's perfectly ok to drive without a steering stabilizer. In fact I like to do that after changing anything in the steering so I can feel what's going on. The steering stabilizers job is to dampen the steering system to help eliminate harmonics, but with good parts properly installed it's not so needed.

Wall-O-Words...

Agree. Wife was a vibe and acoustics engineer before retiring. We habla about this stuff often. What rubbed off on me was that a damper's job is to change the natural (resonant) frequency of the steering/suspension system. In our Jeeps, the lateral flexibility of the suspension, the weight of the axle assembly (with tires, etc.), and rotating mass, all combine to make for a given natural frequency. When the tires strike a bump in the road and deflect laterally at some velocity, they can "excite" the natural frequency of the suspension system and cause a wobble. If the combination of these things aligns, it can cause a divergent vibration we call "death wobble". If it's not a divergent vibration, it we get a vibration and it self corrects and damps itself eventually. Each element of the steering, suspension, tires, wheels, disk brake rotors, hub bearings, axle weight, steering damper, etc., all combine to create a natural frequency. Change any of these elements and the natural frequency changes.

A weak track bar that acts like a softer spring. A strong trackbar acts like a strong spring. So a given force will deflect it laterally either way. We are just pushing the natural frequency higher when we add stiffness in the trackbar. That means we'd get death wobble at some higher speed. The goal is to push that natural frequency high enough, we never encounter it at the speeds we drive.

Loose steering or suspension connections, worn components, heavier tires, all tend to lower the natural frequency associated with death wobble.

Sponsored