Well it runs. What runs? My project, that’s what, and it runs quite well to add to all the labor and $$$ invested. And what difficulties did I encounter? Well none of them have been plumbing or fastening problems for sure.

The extensive use of aeronautical hardware in critical locations on my project is one aspect of ‘overbuild’ protection that I subscribe to. I am not saying that Detroit engineers were wrong in the selection of fasteners used to screw my car together. Many of those same fasteners are still there thirty plus years later.

However when servicing some of the more critical joints on ones project the re-use of fasteners should be carefully considered. This is most important when it comes to any kind of severe use, or when that extra margin of safety will allow you to sleep at night.

Lets take a real world example to illustrate exactly what I am talking about. The lower control arm bolt. How many of you have ever considered replacing these when you had the front end apart in the driveway making a huge mess?

You went through all the trouble to clean ten years of road debris from your control arms and you installed new bushings, ball joints and you’re going to use the same bolts? It’s amazing that people don’t crash and burn more often.

When you make up your mind to replace those worn out and stretched control arm bolts don’t make the same mistake the factory often does. Use a fastener with the proper grip length. The proper what? Here, I’ll show ya’

In order to obtain the proper grip length, measure the width of the center sleeve, and the thickness of the frame material. The sum of their thicknesses is your grip length. You will probably discover that few bolts will be the correct grip lengths without the use of some kind of washer.

By all means, keep the threads out of the holes in the frame. The thread is a huge stress riser in a joint of this type. Just like hanging a sign out there, “break here”. Worse still is when things are allowed to start moving around (bumping a curb) the threads that are in the hole in the frame act like a saw.

Guess what happens to the hole. If the frame has been egged out at the control arm mounting points, it can be reamed to accept the next larger size fastener. Oversize fasteners are available in the aircraft industry in thousandths of inch increments, however they are expensive and usually not necessary.

Test fit the fasteners to be sure that you can see about .100” of shank protruding through the frame. Add two flat .062 washers and a self-locking nut and you’re there.

Don’t bother with the lock washer, they usually destroy the frame, or spread open when the sharp end digs in. Be sure to use a torque wrench, and put the weight of the vehicle on the joint before final tensioning of the fastener.