Steering idea

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GWag89
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Steering idea

Post by GWag89 »

I was checking out a friends 97 Grand Cherokee and spotted this steering set up. It's a kit from iron rock offroad that moves the tie rod over the knuckle, and the drag link under the knuckle.

I understand the potential benefits from heim joints and increased ground clearance on the tie rod all while maintaining double sheer mounting.... On the other hand I have questions about this because I've never seen ANYTHING like this used on a fsj.

Has anyone ever ran a steering set up like this on their FSJ? How did it work? Pros, Cons?

Image

Herk
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Re: Steering idea

Post by Herk »

Why would you want to pieces of linkage to cross each other if not absolutely necessary?

There are "crossover steering" kits out there for TJ's (same basic front end) that change the steering linkage to this configuration. Like drop Pittman arms, just because somebody sells one, it isn't always an upgrade. Unless vagueness on center and bumpsteer are upgrades. Look at the above picture, draw a line from the pivot points on the drag link and compare to a line between the pivots on the track bar. The lines are not parallel, so there will be bumpsteer.

Then there's the open heim joints...
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GWag89
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Post by GWag89 »

I agree with you herk. This looks sketchy to me. Since I don't have any experience or expertise on this matter I decided to ask around before casting uninformed judgment.

SJTD
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Re: Steering idea

Post by SJTD »

Looks like they did that to get the tie rod a few inches higher. Otherwise the tie rod would be under the knuckle and the drag link above it.

I'm not impressed with heim joints either.
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carnuck
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Re: Steering idea

Post by carnuck »

In some states Heims aren't legal for on road steering due to their high failure rate.
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GWag89
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Re: Steering idea

Post by GWag89 »

SJTD wrote:Looks like they did that to get the tie rod a few inches higher. Otherwise the tie rod would be under the knuckle and the drag link above it.

I'm not impressed with heim joints either.
That is what I thought as well. But apparently the way it's pictured is the intended method of instillation.

http://www.ironrockoffroad.com/Merchant ... y_Code=PFZ

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Re: Steering idea

Post by kathyrose »

It is looking abnormal to me. Steering based on kingpins and with negligible cross bars is more safe, i think.

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Re: Steering idea

Post by serehill »

I seriously hope this is an off road only rig. This thing would have bump steer & all kinds of Gyrations from that sway bar angle.
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Re: Steering idea

Post by Stuka »

The only reason that steering is that way is because he has coils. The drag link has to be perfectly in-line with the trac-bar or you get death wobble.

The angle is 100% normal for coil rigs with trac-bars that mount there. If you move the drag link up higher, you have to change the trac-bar to match it. Also, there is no bump steer caused by this setup because the trac-bar travels in the same arch as the drag link.

You do not have to worry about this on a leaf sprung vehicle.
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acct21
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Re: Steering idea

Post by acct21 »

GWag89 wrote:all while maintaining double sheer mounting....

Image
That looks an awful lot like a standard heim setup with the mounting bolt in single shear.

Single shear:

Image

Double shear:

Image
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Re: Steering idea

Post by SJTD »

Stuka wrote:The only reason that steering is that way is because he has coils. The drag link has to be perfectly in-line with the trac-bar or you get death wobble.

The angle is 100% normal for coil rigs with trac-bars that mount there. If you move the drag link up higher, you have to change the trac-bar to match it. Also, there is no bump steer caused by this setup because the trac-bar travels in the same arch as the drag link.

You do not have to worry about this on a leaf sprung vehicle.
If the drag link were higher he could get by without so much drop on the pitman arm and still keep the track bar and drag link parallel.

But then the double shear set up acct21 showed would be necessary if you wanted both the tie rod and drag link above the knuckle. But if doing that why not high steer?

Even better is tapered holes that don't rely on bubba properly reaming the knuckle for the bolt which even if done nice and tight still relies on the bolt torque to keep things from moving.
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'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.
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GWag89
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Post by GWag89 »

You are correct acc

I said that wrong.Thanks for the clarification!
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GWag89
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Re: Steering idea

Post by GWag89 »

Stuka wrote:The only reason that steering is that way is because he has coils. The drag link has to be perfectly in-line with the trac-bar or you get death wobble.

The angle is 100% normal for coil rigs with trac-bars that mount there. If you move the drag link up higher, you have to change the trac-bar to match it. Also, there is no bump steer caused by this setup because the trac-bar travels in the same arch as the drag link.

You do not have to worry about this on a leaf sprung vehicle.
He drives it aground town and to trails near by. It gets trailered on long trips

Are you saying this steering configuration will not cause bump steer on a leaf sprung vehicle?

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Re: Steering idea

Post by SJTD »

A leaf sprung vehicle will always have bump steer unless it has a trac bar parallel to the drag link. The greater the angle of the drag link, the worse the effect.
Sic friatur crustulum

'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.

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Re: Steering idea

Post by serehill »

I see what Stuka is saying & understand. I suppose that's cool especially for articulation. My Bad but i'll still pass.
Last edited by serehill on Tue Feb 10, 2015 7:15 pm, edited 2 times in total.
1980 Honcho 258 4 speed mostly stock with 4 " lift.

WIP

You know the rude dude from IFSJA


1980 Cherokee wrangled & mangled
MSD complete system
Eddy intake
Holley 650
Comp cam 270H
4" Rusty's
Ramsey 12K winch
208
Built to drive not sit in the garage.


No longer strangled. I didn't build it for anyone else.
If you can't improve it why waste your time?
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Stuka
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Re: Steering idea

Post by Stuka »

GWag89 wrote:
Stuka wrote:The only reason that steering is that way is because he has coils. The drag link has to be perfectly in-line with the trac-bar or you get death wobble.

The angle is 100% normal for coil rigs with trac-bars that mount there. If you move the drag link up higher, you have to change the trac-bar to match it. Also, there is no bump steer caused by this setup because the trac-bar travels in the same arch as the drag link.

You do not have to worry about this on a leaf sprung vehicle.
He drives it aground town and to trails near by. It gets trailered on long trips

Are you saying this steering configuration will not cause bump steer on a leaf sprung vehicle?
As SJTD said, I am saying it would cause bump steer with leaf springs (unless it had a trac-bar), but NOT on a coil sprung vehicle.

I can show you the steering on my JK and its an an angle too. Zero bump steer. Because as the axle compresses, it also gets pushed to the side as the trac-bar flattens out. The drag link follows this arc, so it doesn't push on the knuckle. With leaf springs (with no trac-bar) the axle moves straight up, but the drag link does not. So it pushes on the knuckle causing the vehicle to dart to the right.
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Herk
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Re: Steering idea

Post by Herk »

The difference on XJ, TJ, ZJ, JK etc steering is the drag link attaches to the tie rod away from the right knuckle. The axle rotates mostly around the lower track bar pivot. So, with the wheels straight ahead the steering pivot is where the drag link connects which is right in front of the track bar pivot. Everything remains parallel over a greater range of axle articulation. Less bump steer is the result.

The above configuration was used on FSJ's and other post 1970 leaf spring Jeeps, with the exception of the linkages crossing and the tie rod being above the knuckle arms. The steeper the drag link angle, the greater the bump steer as anyone with a lifted leaf spring rig knows. The high steer type knuckles are a better solution.
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Re: Steering idea

Post by Stuka »

Herk wrote:The difference on XJ, TJ, ZJ, JK etc steering is the drag link attaches to the tie rod away from the right knuckle. The axle rotates mostly around the lower track bar pivot. So, with the wheels straight ahead the steering pivot is where the drag link connects which is right in front of the track bar pivot. Everything remains parallel over a greater range of axle articulation. Less bump steer is the result.

The above configuration was used on FSJ's and other post 1970 leaf spring Jeeps, with the exception of the linkages crossing and the tie rod being above the knuckle arms. The steeper the drag link angle, the greater the bump steer as anyone with a lifted leaf spring rig knows. The high steer type knuckles are a better solution.
JKs do not use the Y system from TJ/XJ/ZJ Jeeps. I cannot stand the stock Y steering system on those. The JKs works great.

Stock JK system:

Image
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Herk
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Re: Steering idea

Post by Herk »

I'll admit I'm not familiar with JK's and never really wanted to be.
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GWag89
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Post by GWag89 »

So...basically as long as the steering is relatively flat and the track bar angle mirrors the drag link everything will be manageable
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