Original 427 Street Cobra Suspension Rebuild

[David Kirkham]

What the heck,

While I am here, I might as well post a few more pictures.

Now, for the most miserable job on a Cobra. (Well, there are more miserable jobs--like having to SELL your Cobra because of a divorce...)

ALIGNMENT ON AN ORIGINAL 427 STREET COBRA!

The only thing worse is alignment on an original 289 Cobra! (One day I will post that).

Notice we use a 4 wheel alignment system. That is because it is nice to have all 4 wheels going in the same direction! We asked the Hunter rep for the alignment specs for a Cobra!

[David Kirkham]

Here is a close up of the screen. LOTS of things you HAVE to pay attention to. When you change one thing, other things change! It is like riding on a merry go round. One of the particularly maddening things is tightening up the rod ends when you have everything "perfect." Just tightening up the rod ends changes the angles!!! So, you have to keep trying until it is PERFECT! When these cars are perfectly aligned...magic happens.

[David Kirkham]

Here is our set up. Wires EVERYWHERE!!!

We place sliding turn plates (the red plates) on ALL 4 WHEELS. VERY IMPORTANT!!!

As the wheels travel up and down, they travel on an arc. So, when the wheels are in full droop the track of the vehicle is actually SMALLER than when it is at ride height. As the car settles down from the lift, the wheels SPREAD out and so you have to have plates that SLIDE to take up the movement. If you don't have the sliding plates, the tires will simply stick to the ground and the car will not settle to ride height. It is VERY BAD to align the car when it is not at ride height!

Also, notice we have scales (the dark grey boxes) under each of the 4 corners of the vehicle. We will get into why we do that a little later.

[David Kirkham]

A-Snake,

Good question!

The inner tie rod was worn quite badly on the socket joint where it attaches to the rack. We could "rebuild" it, but it would be VERY expensive as we would have to make new inner tie rods. "Rebuilding usually includes "replacing" a LOT of parts! We would have to make new inner tie rod races as well. Because they are in effect bearings we would have to make them out of a hardenable material and get the Rockwell at least into the very high 50's. Ideally, they would be made out of 17-4 H1150 and then nitrided but then the tie rods would be about $1000 each! Fine for the space shuttle, but not too good a choice for us mere mortals.

You could probably get away with making them in 17-4 H900 and then just running them. The would not rust that way and would PROBABLY last forever. But, they would only be in the low to mid 40's Rockwell C which is NOT enough for a bearing. They would wear out before the automotive standard of 50,000-100,000 miles. But with as many miles as THIS car is likely to see they would probably be fine.

Now you are starting to see the problems we face with these cars! It is all a game of compromises. If you use a nice steel that you can harden--it will rust. If you use a nice stainless that will not rust, you can't get it hard enough to turn into a bearing surface without horribly expensive processes--like nitriding. It is enough to keep me up at night practicing Chopin! Now you know why I play the piano so much. I have to clear my mind so I don't think about how to prevent rust and prevent Cobras from going on unintended off road excursions all day long!

That is the long answer and I feel like Harry Reid--long winded and waxing eloquent about nothing--and not anywhere near answering the question.

Short answer...

Yes, we could rebuild it, but it would probably cost several thousand dollars because the parts are no longer available and they would have to be custom made. In addition, the rebuild would take a month to make all the parts. So, we just replaced the rack until we have time (and enough racks) to rebuild them all at once and make it cost effective.