Rod Ends in the Steering System

[wellis77]

I recently purchased a Woodward Steering rack for my build and it's awesome! In addition, I had them build aluminum tie rod adjusting sleeves (for the front and rear) for me as well. As I begin to plan the rest of the system I have a question on choice of rod ends for the tie rods.

I'm looking at the QA1 Endura series rod ends in either aluminum and chrome moly. The main differences between the two are weight, aluminum is 50% lighter, and the Radial Static Load, aluminum is 15,000 lbs and Chromo is 23,542 lbs. I don't know what sort of forces these will see, but considering the difference in radial static load, should I stay away from the aluminum or is there no reason for concern? Since my adjusting sleeves are aluminum, should I only consider aluminum rod ends?

These will be used of course on the front end but also on the rear IRS.

https://static1.pt-content.com/images/pt/2011/09/file79-1.jpg

[Bryce]

I use 3G for my factor of safety for steering. Same concept that I used on my watts link.

I used Aurora aluminum rod ends with 5/8-18 thread and 1/2" ball.

Multiply the front end weight by 3 and that will give you an estimated max load the rod ends could see.

Rule of thumb for fatigue loads: if the fatigue loads are less than 20% of the ultimate strength then you are ok.

[wellis77]

Good rule Bryce, thanks. By fatigue loads, are you referring to the estimated max load using the 3G factor or is that another calculation? If so, going by this rule, in order to use these rod ends my front end would have to weigh 1,000 lbs. Do I understand that right?

Did you buy your ends direct from QA1 or were you able to find a better price from a dealer?

EDIT: Just realized you said your rod ends are Aurora, not Endura... I'll have to check those out and compare to the QA1.

[silver69camaro]

My method is a bit different in that I calculate the outside tire load in a worst-case scenario (say, a 1.2G corner), then use a factor of safety of 3 to 5 depending on the system.

In my own Camaro, the theoretical outside front tire load is 1480lbs in a steady-state corner, and applying max brake will increase that another couple hundred pounds. A worst case scenario would be cornering at 1.0+g, hitting the brakes, then hitting a pothole...that would be a pretty serious load to the system.

[wellis77]

That sounds great, and realistic, but how does the average Joe calculate all that with a car in production?