A friend and I tried to put winter tires on my car today, but we couldn't get the all-season tires off. First I tried kicking them, hitting them with a hammer, and then a big sledge hammer. I then loosened the nuts and drove up onto the curb, and swerved back and forth, but nothing worked, they're rusted on tight. The car is a 2010, and these winter tires were on last winter and removed in the spring. The ideal solution would be to sell the winter tires and move south, but that's not practical yet. Google doesn't have any more suggestions - what can I do?– A., Halifax
Bill Gray knows what your wheels did last summer.
"What happens to some vehicles with aluminum wheels is the centre hub and the steel car hub fuse together," says Gray, owner of Gray's Auto in Halifax. "It happens everywhere but we see it more often here."
The culprit is corrosion – an electrochemical reaction between metal and oxygen when metal is exposed to water. The metal gets eaten away as it surrenders electrons to the oxygen. Salt makes it happen faster. Halifax has plenty of water and salt.
"Our moist sea air creates a hot bed for corrosion," says Dalhousie University engineering professor Stephen Corbin. "If he parked his car in a warm moist area like a garage or spent a lot of time by the seaside, that could speed up corrosion."
The fusing is confusing, though. It doesn't happen at all with steel wheels on steel hubs, because they're both the same material.
And it doesn't happen with every aluminum alloy wheel.
Some metals corrode more easily than others. When an active metal (a metal that corrodes easily) is touching a less active metal (a metal that doesn't corrode easily), the two form a galvanic couple, Corbin says.
"The active metal has the highest potential to corrode and the presence of the less active metal shifts the balance such that the active metal corrodes even more," Corbin says.
So, if the iron in the steel hubs is in contact with aluminum in the alloy wheels (say, if the inside coating of the wheel is scratched) – the steel corrodes faster than it would on its own.
"This type of corrosion usually concentrates at the contact between the two metals and could cause them to bind together at that contact," Corbin says.
So, those all seasons can get stuck on in just a season or two.
How do you break the bond without wrecking the wheel, or worse? First, get the wheels safely off the ground, Gray says. And that might be tough for home mechanics.
"Jacks are unsafe – somebody at home could kill themselves if they move the car off the jacks," Gray says. "I wouldn't recommend someone at home doing this unless the car is safely supported on (jack) stands – and I've yet to see and average Joe have jack stands and make them secure."
Then, they try a few things – all while keeping on one lug nut so the tire doesn't fly off.
"Every case is a little different," Gray says. "We'll get out a mallet and hit the inside of the tire with a mallet or we'll use a long bar to pry them off."
Gray's suggestion? Yep, bring it into a shop and pay $20-25 for them to put your winter tires on for you.
"You're saving yourself a lot of aggravation," he says. "Although, in Toronto, that could probably be $120."
After the wheels are off, they clean the inside face of the wheel and the hub with a wire brush or sand paper.
"Then we apply a thin coat of lithium grease to the sanded areas, being careful not to lube the wheel studs," Gray says. "Grease on the studs messes up the torque, so it's a no no."
The grease separates the aluminum and the steel and repels water – and Corbin suspects that the lithium in the grease takes one for the team. Oxygen reacts with the lithium, instead of with the steel and aluminum.
"Any oxygen that does managed to get near the steel/aluminum contact will combine with the lithium and not the steel," he says.
A little grease is cheaper than a move to Arizona, but there's controversy, on the Internet at least, over whether or not anti-seize lubricants should be used on wheel studs – or on wheels at all. I'll leave that for another column.
And, like you said, a Google search rustles up of other suggestions for removing a rusted wheel. For example, The Family Handyman magazine suggests getting the car off the ground, using a spray-on rust penetrator and then hitting a piece of wood held against the outside of wheel until it loosens up.
Readers, if you've been in this sticky situation or you have any tips of your own, please join the discussion.
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