Ever watch video about how to do a car repair, where the host breezes through it in just a few minutes, but in your garage it ends up taking all day? Often that disparity comes from wrestling with rusted bolts.

“All cars have rusty nuts and bolts, especially those under the vehicle and associated with the hot exhaust system,” says master-certified technician Chris “Moose” Pyle. “The road salt states are the worst, especially in the north where the salt is under the car for months, eating away at the metal. Those are a real pain.”

Rusty bolts are also common around the steering, suspension and frame. Luckily, it’s not too terrible of a task to remove them with the right tools.

“The first plan of attack is penetrating lube, a wrench, socket or air impact gun,” says Pyle. “If that fails, you may have to move up to heating the area and using a bolt extractor. And if that fails, you can cut it or grind it off.”

If you’re struggling with an aggravating, rusty bolt, here’s a quick fix for an otherwise frustrating task.

cut off tool

Every time I hit a bump in my Honda van, I heard clattering metal parts in the front. The problem was easy to diagnose by simply looking behind the wheels. Both sway bar linkage ends were completely separated and dangling.

After rounding up the new sway bar linkage parts, I jacked up the van and tried to remove the nuts holding the linkage arms. But it was clear that no amount of penetrating oil was going to loosen those 13-year-old nuts. The space was too tight for a regular angle grinder, and difficult to reach with a reciprocating saw, so I pulled out my 3-in. cutoff tool and proceeded to cut through the nuts and bolts.

There may be more robust versions of it, but this $35 tool is fine for occasional use. I was able to cut through the bolts in three or four minutes. But I found you have to use very light pressure or the motor will overheat, causing the thermal overload switch to trip. I guess this is a good thing, because otherwise the motor would fry. You can buy this cutoff tool from Harbor Freight. Even though the tool isn’t very powerful, considering the relatively low cost I think it’s worth having around for situations just like this.

FAQ

How can I prevent future rusting of bolts?

To help prevent or mitigate rusting bolts, regularly clean your car, including the undercarriage. Another option is coating underside with rubberized undercoating or black spray paint, says Pyle.

“No lie, I’ve also seen older adults who mix gear or hydraulic oil with diesel fuel, then soak the underside with a bug sprayer each year,” says Pyle. “Although not great for the environment, it works very well.”

Will cutting the bolt damage the surrounding components?

Yes, cutting off stubborn bolts often damages the area around them.

“But the process normally occurs under the car, where appearance does not matter,” says Pyle. “If you take care to do it right, the resulting damage can be none or minimal.”

About the Expert

  • Chris “Moose” Pyle is a master-certified technician with 20-plus years of automotive experience. He has also worked as an expert for JustAnswer since 2006, where he answers hundreds of car maintenance and repair questions a day.