1955 Ford Part 103: Troubleshooting a Belt Squeal on the Vintage Air Setup...

Updated: Jun 2

There is nothing more annoying than an engine drive belt that makes noise! Over the past several months the 1955 Ford Fairlane had developed a belt squeal on initial startup and at any time there was a serious load calling out for more amps. (Recently when I was cruising with the headlights on, fog lights on, and hit the horn for an extended amount of time the belt squealed as the alternator kicked in to give out the juice.) If you want to see the video of how I tackled such a problem when I thought my belt had enough tension, you can scroll down to the video below and have some fun watching me chase the issue. Needless to say I am glad it has been resolved.

My first inclination was that since the belt was tight enough there had to be slippage going on with either the groove of the alternator pulley or the belt itself. So, I removed the alternator. Keep in mind that with the Vintage Air Y Block bracket setup for a Sandeen compressor and alternator mount on the passenger side, the compressor belt has to be removed first.

The view from underneath the Vintage Air bracket setup

The alternator belt was next of course, and after removal I examined both the alternator pulley and the belt itself. You can see from the photo below that the groove of the pulley looks rather smooth. I took some 60 grit sandpaper and roughed it up quite a bit so that the belt could "bite" a little better.

Both belts were treated with 303 Aerospace Protectant. This is a relatively new product on the market that is hard to find locally without having it shipped, but its properties are fabulous. It is really a rubber rejuvenator, NOT a product like Armor All.

I sprayed both belts liberally and allowed them to dry in the sun. The affect of the 303 Aerospace Protectant was simply fabulous. The belts did not become sticky per se, but they did come back to life with great friction properties along their "V" surfaces. I was very happy with the results and can highly recommend the 303 Aerospace product. One word though - the stuff is not cheap. From my math it was almost $1 an ounce!

The belts were re-installed and I fired up the engine... NO SQUEAL! Good news, right? Well, I thought it was but when I looked at my dash I noticed my Gen light was still glowing. Aaargh! "What could this be?" I had set up a video camera to capture the motion of the alternator upon startup and after reviewing the footage I could see that the pulley was locked up and not moving at all. Odd.

I loosened the alternator belt and removed the alternator from the bracket... the picture below shows the telltale signs of the alternator's cooling blades scraping the radius of the bracket! Evidently, the blades were locking up against the bracket causing the alternator not to spin freely.

I removed the hardware, spacers, and the alternator mount, with the plan to grind away some metal to create room. The fix was pretty simple as shown in the photo below and the video of my troubleshooting process. I did not have to grind away too much to create the space needed along the curve of the mounting plate. Before re-installing I did hit it with some fresh paint.

How I did not catch all of this seven years ago when I installed the Vintage Air setup originally I have no idea, but it was certainly obvious. Once I hooked up the belt and set everything straight I fired up the 292 Y block a few times and the squeal was gone. Oh happy day! The edited video is only about 11 minutes long, but it does a little better job in showing some of the Vintage Air parts and pieces, and of course the annoying sound that the belt was making.

Video of Troubleshooting the Vintage Air Alternator/AC Bracket

The Hot Rod Reverend

aka Daniel Jessup