Rust protection on vehicles essential

Mechanic, colleague and allaround swell fella Brian Early emailed from Oshawa, Ontario with a scary story and photos a few weeks back.

His story illustrates the importance of two things: the potential importance of applying rust protection to your ride if it’ll be used during Canadian winters, and the importance of taking your mechanic’s advice seriously.

Early had a customer arrive, complaining of a ‘funny’ feel to the steering, and saying that the vehicle was behaving oddly.

According to Early, this customer and several family members are semi-regular visitors to his shop, and he’d seen the car on numerous occasions before. “We’ve seen this car, on and off, for quite a while,” Early says. “This time, the customer described the problem to me, as being as if “the car was drunk. This was an accurate description, and my brief test-drive was eye-opening.”

The vehicle’s handling, and directional stability, were substantially reduced and just a quick test-drive was enough for Early to determine that something was drastically wrong. Early says there was more than a quarter-turn of free play in the steering wheel, which, among other things, is a huge safety concern.

After looking beneath the car on his hoist, Early quickly found the problem.

“The sheetmetal tab holding one side of the steering rack had broken off, allowing the whole thing to pivot upwards on the other horizontally positioned mounting bolt. So, instead of pushing the rear of the front passenger tire to the right as normal, to turn left, the steering rack would first deflect upwards until it hit the body, causing dramatic toe angle changes, and a highly variable response to steering inputs.”

In simple terms? The steering rack was hanging off of the car. Why? Rust. Corrosion had, literally, eaten through the subframe, and in particular, at the location where the steering rack mounts to that front subframe. Proper steering requires a vehicle’s power steering rack to be fixed firmly in place, but because of corrosion, this steering rack was free to move around.

“We’re big proponents of oil spray style rust prevention, even though we don’t sell it here,” Early adds. “But we’re realistic that it only slows rust and doesn’t stop or outright prevent it, particularly if the vehicle wasn’t treated right from new. For several years, we’ve suggested to this car’s owner that she have it sprayed, because it was getting scaly and dry in places. But the car gets driven less than 10 km per day, so maybe the customer didn’t think it was a worthwhile expenditure. And to be fair, the visible parts of the car still look to be in good shape. This is not unusual.”

Early notes that in many cases, components like vehicle subframes only use paint as a means of protecting them from corrosion, unlike vehicle body panels, which are typically galvanized, or have additional corrosion protection built in.

“This is why a visual check of the surface of the car is no substitute for a periodic check underneath for more excessive rusting,” he adds.

The customer’s Pontiac Grand Am was repaired with a used subframe sourced from a wrecker, and Early also changed a long-broken stabilizer bar with a new unit as part of the overall repair, while he was at it. In this case, the customer got lucky as an issue like this can often wind up writing a vehicle off.

“I’ve personally replaced several subframes and cradles, and have condemned quite a few other cars that weren’t worth repairing,” Early says. “This 2005 Grand Am has just under 100,000 km, and the owner decided it was better to spend the money on the repair than to shop for another used vehicle.” Perhaps due to our climate, Early says this is a fairly common occurrence.

Brake and fuel lines are a far more frequent failure, but subframe and underbody structural rot is a more common of an issue than you might suspect. Money wise, Early figures that annual rust-proofing, which runs about $120-$160, is a worthwhile investment, compared to repairing a rotted subframe.

“You’ve got to figure about $300 to $600 for a decent used part, and anything from $300 to $1,000 in labour to replace it. Plus, whatever things break or die or have to be replaced during the swap — including fluids, and exhaust components.”