Technical Need Source for Heavy Duty Tie Rod and Drag link tubing

My 2001 F350 Superduty 4x4 has a solid front axle (D50) not IFS and it has the tie rod out front also and judging where the connection is in relation to the ball joint Akerman wasn't an obvious concern there.

 

You are comparing apples to kumquats

 

Yes and no, the rules should still apply, yes?. Tie rod and ball joint turning a knuck or spindle.

 

And please don't read what I am not saying. I am not arguing, mine is not correct. I get that. Now I am trying to learn

 

So talk to me about dropped steering arms. If I can stay above scrub line and drop below the frame with enough room for suspension (what seems typical suspension travel?) Are those ok? That could put the tie rod behind...Maybe

 

I can****ure you that there is a significant offset between the tie rod pivot, and the ball joint pivot on that axle.

I can probably find you a picture.

 

Here's the fix.

Buy a dropped axle. A model a axle had some drop in it already. A dropped one will bring that total to about 4".

The actual amount that gets it there is about 2-1/4".

Re-mount your spring lower on the mount by that amount (minimal fabrication).

Obtain deep drop steering arms, mount them, and put the tie rod underneath, behind the axle.

If that sounds like too much, get those same steering arms, swap sides, and mount them upside-down, with the tie rod in the back. Rework anything in the way.

 

This is an online stock photo of a Dana 60 but tie rod ends on tie rod are narrower than the ball joints.

 

You can ask @Pocket Nick who influenced him to move his tie rod (and where he got those 45-fin drums).

 

Thank you, this is what i was just asking. I will look it over tomorrow to see what would need to change to swap them to behind the axle and still have clearance. Fingers crossed.

 

It was common practice to bend forged Ford axles to align them for camber, and still is today for heavy trucks. With use, in a collision, or tweaked from potholes and the harsh roads of the day, the only way to get proper camber is bend them. A cheap off-shore cast iron axle cannot be bent, they break, but forged are malleable and can be heated and bent.

 

There is an alternative way to get the tie rod on the back side. You can mount the tie rod arms to the top two backing plate bolts so it's above instead of bending arms to get the clearance you might want. Then simply add a third arm on the lower two bolts to attach your drag link.
Flipping the arms to the top, and maybe side to side if it needs to allow clearance all work, and can sometimes save you a lot of fabrication to change everything.

 

So the Pete and Jake's deep drop steering arms drop them 3.75". If tie rod is moved to behind the axle, and use those arms, I would have 1.75" of upward travel of the travel as is and be right at the scrub line of a bare rim. So if I raised the car even an inch scrub would be better. How much room do you guys typically give yourself ...tie rod to frame or other non suspension traveling parts?

 

RE: Ackerman.
I think like many things it can be a question of degree.

For most street driving other than parking I'm guessing the driver will be turning the steering wheel less than 1 full turn from center. And driving down the highway probably less than 90°.

Achieving perfect Ackerman at full lock even on cars with rear mounted steering arms is probably not going to happen.
I say that because when walking/waiting in parking garages with polished painted floors there is nearly constant noise as the inner tires on most cars making even medium sharp turns squeal like a pig.

I wonder if testing to determine insufficient low speed ackerman might be as simple as pushing the car 3a few feet forward and back by hand with the wheels straight and then with with the steering wheel turned + and - 90°.

Volvo 240s have a wonderfully tight 32.2 foot turning circle. Their steering arms and steering rack are forward mounted.
https://images.simplepart.com/images/parts/volvo/fullsize/GR-64674.jpg
The only time I am aware of tire fight/scrub/drag on my VERY tight turning 240 wagon is when turning on sandy asphalt.

For spirited driving ackerman may be a pretty minor concern.

Attached is some info from the noted Milliken book.

The late great Carroll Smith certainly had some success developing good handling race cars.
In Tune to Win he said this -

 

No, they are not. You cannot see the alignment line in that picture.

Please stop.

From the correct perspective, it is plain as day that the tie rod pivots are farther apart than the centerline of the ball joints!

 

This is a descriptor of conditions and forces that are far in excess of normal street driving, where the consequences are meeting a well designed safety barrier, and where tire wear is not a primary concern.

Please do not bring the dynamics of race car suspension and steering to a conversation about a lightweight street car that has been built without a safety cage.

You will only confuse the matter, and encourage the OP to make bad decisions based on information that is not applicable to his situation.

 

On the picture you have of the truck steering.........I'm GUESSing that the trucks being so heavy and using much larger tires and wheels, they just accept the fact that its going to wear the tires when turning.

On the simplistic picture of Akerman that I provided earlier.......I don't see where having the tie rod in front of the axle would not work ..........as long as the attachment point still followed the same line from the rear and passed thru the kingpin centerline........as long as there was room to clear the front wheel. In the diagram, it doesn't look like its possible, but on a real vehicle there actually might be more room to make it work. Again, just guessing.........

 

For the record, I am not confused and actively asking questions to move the steering to the rear. My latest concern is the amount of suspension travel with an model A spring. My question:


So the Pete and Jake's deep drop steering arms drop them 3.75". If tie rod is moved to behind the axle, and use those arms, I would have 1.75" of upward travel of the travel as is and be right at the scrub line of a bare rim. So if I raised the car even an inch scrub would be better. How much room do you guys typically give yourself ...tie rod to frame or other non suspension traveling parts?

 

I recently had a customer's car in the shop with a Dodge Hemi up front.

Even with all that weight, it has 2-3/4" of compression travel, as measured by the zip ties on the shock shafts, and corrected for shock angle.

Keep in mind that the drop in a steering arm does not take into account how the tie rod end is mounted to it.

On most dropped steering arms, the tie rod can be mounted below the arm, putting the tie rod tube another 1-1/4" below the arm.

Remember, scrub line in this case is: "rolled both front tires off of the wheels, and the metal of each wheel lip is now on the ground". You only need a credit card thickness clearance if that happens (and new underwear).

I have never fully understood the scrub line argument in terms of the physics of vehicle operation.

If both of your front wheel lips are metal on road, you are not going to be using your steering or brakes anyways. You will already be out-of-control.

 

I ordered the deep drop arms and made a temporary 1" lift block to raise the frame for more tie rod room. We will see what it all does. I should be above scrub line and still have 2" or so of room. If not I can raise another inch.

 

This is a very interesting thread. Usually when guys with a new car come to the HAMB and ask why it steers badly, we get a lot of good advice from members. But then the OP says we are all wrong and he goes on his merry way. Gladly this time Demon is willing to listen and is actively making changes to better his situation based on the sound advice he received. Good luck Demon!

 

Agreed. Hot rudders is a brotherhood of sorts. To the motoring public we are all the same. When one of our vehicles is in an accident the negative press and potential legislation affects us all. So we try to steer each other towards safe builds, regardless of style. We don't want anyone representing us in as Ralph Nader said in " vehicles unsafe at any speed. We don't do it just to be "A" holes.

 

How much clearance you need really depends on axle travel, or spring compression. I was helping a friend with a front shock bracket on his '27 Ford roadster pickup yesterday, which was built by So Cal and I asked if his front axle ever hit the frame rails as it had maybe 1.25" total clearance as it sat. He said it never has hit, and I looked all over for some bump stops, but didn't see any? So I guess his spring is stiff enough to not let the axle hit. The frame is boxed, and C notched for even the small clearance his car has now.

As for front side tie rods, and Ackerman angles; I think it can be made to work, and get the angles close to correct. Close enough to work and drive well, as I've seen more than a few where the steering arms were made to almost touch the wheels up front to correct the issues of a front side tie rod. Drove a few of them also, and they drove really well, and I couldn't notice anything wrong driving them.

 

Yup I think he is on the right track and will get it figured out in no time. I have run out of advice to give so I am just a cheerleader now.

 

It cannot be done properly.

There are automotive engineers on this thread.

Please listen to them. Life might depend on it.

 

Deep drop arms came in. No combination will work. Unfortunate. Would need to raise the front probably 2 more inches. That's above the now 1 inch raise. The thru bolt is just mock up with what I had laying around.

 

I've seen it done on cars that had been on the road for decades. When are they going to lose control and crash?

 

Could be the very next turn, or under the next panic stop. Statistics are rearward looking, and cannot predict anything.

Nobody who died is here to report what killed them.

Plenty of foolish and dangerous things are popular.

A good example is a regular guy arguing vehicle design with a degreed, qualified, and long-tenured automotive engineer.

 

Maybe the engineer should quit arguing & let the lawless proceed ( its still a free country) or move to Australia , New Zealand or other such places , he might fit right in !