Today, we joke about shops that pulled out collision damage using a tree stump and log chains. As a PBE jobber with customers in rural Iowa in the 1970s, I knew some of those guys. When cars were built with perimeter frames and conventional steel, a talented tech could actually get the car square enough to line up the front end (with a box of shims) by using a frame dimension book that listed the specifications for most American cars (in inches) and a tape measure. A good guy could heat and tug until the rails came close to spec.
Stumped
What were those hardy pioneers using to tug with? Once the frame was anchored to the tree stump with unhardened log chains (what breakage problem?), they pulled out the damage using a come-along, a Porta Power ram or the shop truck. Really!
In the ’70s, I sold floor pots and 10-ton pulling towers to lots of those shade tree guys. Not only were 18 or 20 pots easier to use than one oak tree, they laid flush to the floor and didn’t impede other collision work when not in use. Without a rigid mount, the first few extensions of the 10-ton ram were just to pull the slack out of the anchor chains. Jamming jack stands under the chains until they were tighter saved lots of time and moved metal sooner.
Rack ’Em
Anchoring the vehicle frame directly to rigid clamps on a frame rack was even faster yet because the first inch of travel on the ram moved metal. In those early days, only the biggest shops could afford a huge frame rack built into a floor pit, but boy could they unwind some hard hit stuff. Using floor pots and portable pulling towers or free standing racks with built-in towers, we pulled and tugged our way to repair and alignment for many years. And then…the gas crunch of 1973 happened. In a country where bigger was always better, we became miles-per-gallon conscious overnight. It took Detroit until 1979 to mass produce the first of the new frame-less cars, the X-Body General Motors Citation.
Welcome to the New Style
During those intervening years, the first casualty of expensive and scarce gasoline was big V8 engines. The second was the bridge-girder heavy perimeter frame, and the third was the thick, heavy gauge sheet metal. Smaller four-cylinder engines, the three-box unicoupe body construction and the high tensile strength thinner metals hit the industry like a bomb.
Older folks will recall that the Inter-Industry Conference on Auto Collision Repair (I-CAR) was formed to teach our techs how to safely repair these new-style autos. You couldn’t heat the metal with a torch because it ruined the strength. You couldn’t pull on the sheet metal box with 20 tons of hydraulic force because it tore the car apart; and without a perimeter frame, it was difficult to anchor the car rigidly.
In those confusing days of the early ’80s, many shops went shopping for a better method to repair the new unibody vehicles. The choices to hold the frameless car steady, pull the sheet metal in several directions at once and measure the boxes back to exact factory spec fell into three basic styles, all costing about $25,000 in 1980 – a huge blow in an industry where the previous most expensive thing was the $10,000 fireproof box they painted cars in!
Dedicated Benches
Dedicated benches used a jig system similar to the fixtures the bodies were built on at the factory. Each unique body style required a specific set of arms and clamps to locate all the various measuring points.
While unarguably accurate, they were time consuming. The suspension, engine and drivetrain often had to come out of their cradles because those same mounting holes were where the fixture pins went. Some large dealership shops could afford to buy the measuring fixtures for their own models, but most everybody else rented fixtures from the equipment manufacturers. Many times, there was a delay as the fixtures were already rented to another shop and they were slow to return them. Also, if the prior shop misused the fixtures, they could arrive bent and out of spec.
Laser Systems
Laser systems were desirable because they could be used to repair anything, even full frame cars and trucks. In 1980, only about 2 percent of the cars on the road were unicoupes. The shop owned the hanging targets and the laser, so there was no waiting for another source to begin repairs.
I sold several laser measuring systems in the early ’80s and was impressed with their versatility. My customers who did the best with them employed smart technicians. I’ve discovered over the years that not everyone repairing cars is good at math. Using an early laser system required that the tech be able to calculate distances and angles without a specific set of directions. As the systems evolved, the math effort was significantly reduced by exact directions on where to hang targets and where to locate the lasers.
Universal Benches
Universal benches used a box full of pipes and pins and braces much like Tinker Toys, which were stuck together to build a measuring framework. They had the advantage of locating most structural points without removing drive train or suspension components; they were all on-hand so there was no waiting, and the best ones came with exact instructions on how to build the fixtures for each model car. They were quick to use, it was easy to diagnose the damage and they could be used by ordinary technicians. Clearly I’m still a fan, even though the $25,000 cost is more like $75,000 these days.
Measure, Pull and Hold
All three styles – dedicated, universal and laser measuring systems – have a rigid base with pinchweld clamps to hold the unibody completely still and multiple pulling arms to reverse the collision damage in several directions at once. The common wisdom in those early days was that a shop could not repair a hard hit unicoupe car without the three key elements: measure, pull and hold (MPH). I’ve found that talented body techs can do anything, and a skilled guy with the floor pots and a tape measure could get the three-box car straight again. It just took a really long time. They had to pull, cross measure, pull, measure, pull, measure, etc., until they reached spec. Part of the 25 grand entrance fee was quickly recovered because, with any of the three styles, once the pin hit the hole or the laser hit the target, you were done pulling and could move on. Labor time was and is the most expensive thing in collision repair. A rigid hold on the damage, pulling in several directions at once and a go/no go measuring system is much faster than an oak tree and logging chains. Safer, too!
Mark R. Clark is the owner of Professional PBE Systems in Waterloo, Iowa; he is a well-
known industry speaker and consultant. He is celebrating his 25th year as a contributing editor to BodyShop Business.
