Trade secrets

Motor, May 2000 by Cerullo, Bob

Taking a cue from one of history's greatest inventors, Bob uses his curiosity to come up with a unique support system for a subframe swap.

Back in high school, science was a subject that really rang my chimes. I actually couldn't wait to get to class to perform experiments with electricity, chemicals and things mechanical. History, on the other hand, was something I merely endured, until one day the teacher started a discussion about Leonardo da Vinci. Up until then, I associated da Vinci with being a great artist whose best-known paintings I figured we were going to have to learn about. Then the teacher switched on a slide presentation that started out with a color shot of the famous Mona Lisa.

I got ready for a catnap in the darkened classroom. As I drifted toward dreamsville, suddenly an illustration of a model of a primitive helicopter flashed on the screen. I thought, Now wait a minute. This guy da Vinci was born in 14,52, long before the internal combustion engine was invented. In fact, they didn't even have oil, much less gasoline. How could he be drawing helicopters and other flying machines centuries before the Wright brothers flew the first plane?

As one slide after another flashed on the screen, I was amazed to learn that da Vinci was also an incredible inventor and engineer. He designed variable-speed gear devices that are the origins of today's transmissions.

His list of other inventions includes the parachute, designs for a flying machine, gear & pulley systems, lathes, mechanical saws, paddle boats, a printing press, double-hulled boats, multibarreled machine guns, cannons, turbines, rockets and numerous other devices which, like the helicopter, were so far ahead of their time that it would be several centuries before they would actually be built.

That exposure to Leonardo da Vinci opened my eyes to a whole world I had been missing. I took great pleasure in exploring the work of da Vinci in the fields of science and applied mathematics. I couldn't help but wonder how he would have reacted to our modern computerized vehicles and things like the Internet...and what he could have invented if he were alive today.

It seemed to me that da Vinci was a fellow who simply did not believe in the word can't. Over the years, I've taken great inspiration from his determination and ability to use his mind to develop ways to surmount problems that everyone before him probably felt were unsolvable.

I can think of many instances in our shop where jobs were brought to us because another shop threw in the towel and said "It can't be done." As a case in point, let me tell you about a job we took on as a favor to a good friend who owns a body shop. The car was a 2000 Dodge Intrepid that had been hit pretty hard in the right front. The hit caused the bumper support to move rearward about five inches and distorted the subframe holding the engine and transmission. Our job was to replace the subframe, then turn the job back over to the collision shop for the sheet-metal and paint work. In the process of disassembly we also found that the timing case was cracked.

Obviously, if we were going to replace the subframe, we were going to have to support both the engine and transmission while we did the swap. In the past, we've simply hung the engive from a chain hoist hooked to a ceiling beam or supported by a big old A-frame we've been using for years to pull engines. But in this particular instance, we couldn't use the A-frame because it was too narrow, plus we wanted to hove the car on a lift for the repairs. Most importantly; we wanted the engine/transmission assembly mounted securely so it wouldn't budge when everything was unbolted.

We ordered the necessary parts after the insurance adjuster came and looked over the car. While we waited for the parts, we decided to tm a different approach to supporting the engine, but still doing it safely. We fashioned a frame right over die engine compartment and attached it to the stmt towers in the rear and the bumper support up front. For the frame, we used slotted angle steel left over from some shelving we had lying around the shop. Once we cut the pieces to fit, we wound up where we could easily attach predrilled steel straps to the engine in four places for support.

One of the obstacles in the path of the repair was the composite intake plenum that could easily be damaged. So we decided to work around it. In a surprisingly short tune, we had the engine supported securely while still maintaining the ability to raise or lower the lift without worrying about chains or cables connected to an overhead winch. This was important because we weren't sure when the insurance adjuster would arrive for a reinspection of the timing case.

As our frame took shape, there were the usual doubters both in our shop and some visiting mechanics who shook their heads and said the thing would never work. They offered what we deemed well-intentioned ideas and advice on how they "always" do such a job.

Obviously, the frame wasn't in the same league with the things da Vinci conceived, but we all felt kind of good about our homemade contraption, which we now plan to use whenever we need to support an engine/transmission assembly for a similar job.