West Michigan Chapter of the Buick Club of America




    The tow trailer, carrying Del Carpenter’s nearly completed 1929 Ford AA-truck home from its very first showing, was starting to fishtail. Accelerating onto the Interstate, Del felt the tell-tail sway tugging his pickup back and forth. "No problem," he thought as he reached for the tow-vehicle electric-brake control-arm on the steering column. A couple of taps on the lever will straighten out the tow-vehicle and make it settle down behind the pickup.
    Del instinctively reached for the handle – it wasn’t there – it was a new braking system that required him to push a button in. No time to look or feel for the button, the fishtailing trailer was rapidly getting out of hand and required both hands on the steering wheel. His late model heavy duty GMC pickup was now being violently jerked back and forth. Del could see, in his peripheral vision, his white tow-trailer appearing first in one mirror and then the other. This was truly a case of the tail wagging the dog!
    As fast as Del could turn the steering wheel to counter the fishtail, the trailer snapped around to the other side. Del’s mind was racing, "What on earth could have happened that would cause this? Did I forget to hook up the hitch properly?" he wondered. "Or did something break?"
    There wasn’t much time for contemplation. He was doing everything he could to keep from losing control. "How much more can this rig take?" he wondered "If I don’t get it under control, the trailer will flip, rip loose from the pickup and totally destroy my 2-year labor of love," he thought to himself.
    The Ford AA-truck wasn’t just a ‘restoration project’ to Del. It was the same type of truck he had first learned to drive. He tells the story that when he was 6-years old, on his dad’s farm near Ellsworth, Michigan, he was given the job of steering the truck through the potato fields. He stood on the seat, the vehicle was put into first gear and the hand throttle engaged to the point where the workers could walk along side and throw sacks of potatoes onto the bed of the truck. Del couldn’t reach the pedals but he took his job of steering quite seriously. That old truck served them well on the farm and Del grew to love it and the memory of it. His nostalgic memories and two years of hard labor re-creating it from a pile of junk were now within mere seconds of being dashed to pieces on the cold gray concrete of the Interstate.
    The trailer was now whipping back and forth so viciously that Del no longer needed to look in the mirrors to see it. He could actually see it out of the side windows. He could see the trailer raise up on two wheels and smoke the tires as they screamed at sliding sideways on the concrete. The situation was now totally out of control. His biggest fear was that the trailer would come all the way around and give the pickup a sideswiping slap. There was no point in babying this situation any longer as he bore down harder on the brakes. It was imperative that he get the rig stopped as soon as possible. He wondered if the tie-downs would continue to hold the AA-truck down or would he see it burst out of the side of the trailer and seek it’s own destiny. In one final pendulum like swing, the trailer swung itself entirely around, dragging the rear end of the pickup with it.
    And then it was over. The smell of rubber filled Del’s nostrils and for a moment, the only thing he could hear was the sound of blood pumping through his head. As he lifted his eyes, he took stock of the situation – the truck was still upright, the trailer was still upright and his AA-truck hadn’t spilled from it. He then remembered that he was in the middle of the normally busy Interstate. He looked up to see three lanes of traffic backed up, impatiently parked and waiting for him to collect himself. The driver of the car in the center lane, realizing that Del was probably in a state of stock, motioned to him that he should turn his rig around and pull off on the shoulder. Del deliberately complied, parked and exited his vehicle. As fresh air filled his lungs and the adrenaline rush began to subside, he walked around the rig, assessing the damage.

    The "what went wrong" didn’t take Del too long to figure out. Apparently a AA-truck has more weight in the bed, over the rear dual wheels, than over the front. The heavy metal frame, full 2" oak wood bed and stake rack far outweighed the engine and front-end components. When Del drove his AA-truck into the trailer, he had centered it over the axles. Because the trailer was hooked up to the pickup, he didn’t detect that there was no weight on the hitch. The absence of weight on the hitch allowed the trailer to think it was in control instead of dutifully following behind the tow vehicle. Augmented by the inherent flex of the trailer and tow-vehicle tires, the sway quickly amplified itself until it became unmanageable.
    To remedy the situation, Del loosened the tie-down straps and moved the AA-truck forward, until there was a noticeable amount of weight (about 10%) on the hitch. This would prevent the trailer from trying to lead the tow and keep it behind the pickup where it belonged.

    The AA-truck had moved around in the trailer and had to be re-centered. Remarkably, there was no damage to it. It is amazing that the AA-truck it didn’t rip free from the tie-downs and smash through the sides of the trailer.
    The trailer, however, had brushed up against the guardrail and three faint but distinct grooves in the aluminum skin could be seen.
    The weight equalizing bars on the hitch suffered some twisting but could easily be repaired.
    Del’s nerves and pride, however, suffered the most damage. Del had had his "stress-test" and his heart was still beating -- he felt good about that. But, what he didn’t feel good about was how badly he had underestimated the importance of weight distribution. Everything was top-notch: the pickup, the trailer, the hitch, the tires, the tie-downs – and yet, with all his years of experience and knowledge, like an amateur on his first time out, he lost it.
    As he gazed at the black skid marks on the Interstate concrete that he had just left there, he thought of how close he had come to having an accident. His rig was new and was set-up ‘by the book’ – everything was the way it should be – with the exception of weight-distribution in the trailer. That won’t be a mistake he is likely to make again.


  • Tires – A tow vehicle should have LT tires for towing. P tires have softer sidewalls, which can contribute significantly to sway.
  • Tire Pressure – Proper tire pressure for both the tow vehicle and the trailer are crucial. Under-inflated tires contribute to flex, which can contribute to rear-end sway.
  • Tongue Position -- Lower the hitch to tow in a tongue down position. Install a drop-hitch if necessary.
  • Weight Distribution -- Check for proper weight distribution. A good rule of thumb, is about 10% of total trailer weight should be on the tongue.
  • Weight Distributing Bars – This device distributes the tongue weight evenly across the tow vehicle and prevents rear-end sag.
  • Sway Bar – This device provides increased resistance to trailer swaying but please note, a sway bar may mask a problem but not cure it.