Jim and his buddy Tim were doing a pre-run on permitted but seldom-used trails in the vicinity of Tonopah, Nev. back in August. They stopped to check the map and both noticed the smell of burning grass. They did a 360 inspection and found nothing. Wildfires blazed in the Sierras, but were too far away to be the source for this odor. They resumed their drive.
After a full day of driving, Jim stopped for another map check. He noticed smoke and flames billowing up the left side of his vehicle. Jim grabbed his 10 lb. dry chemical fire extinguisher. Lying on the ground he could see 4”-6” flames surrounding the transmission on both sides. A half dozen short blasts on each side of the transmission extinguished the flames.
A thorough inspection revealed that the area above the skid plate had become packed with dried vegetation. The front edge of his skid plate had lopped off the tops of grasses and brush as they rolled along. This vegetation, tinder dry from the hot summer, needed just a heat source to light up. (Later, Jim discovered scorched grasses in the open pocket around the plastic gas tank skid pad. Had that area ignited, he would’ve had a really serious incident on his hands.)
Jim’s experience, though uncommonly severe, serves as a good reminder of a hazard four wheelers can face. Driving through tall or heavy vegetation presents a real fire hazard. Make sure you thoroughly inspect the undercarriage whenever you stop —whether for lunch, photo opps or a 10-100. In fact, it’s not a bad idea to stop frequently if you’re driving in those conditions. It doesn’t take long for the vegetation to build up.
Look inside every nook and cranny underneath. You’ll be surprised where that stuff turns up. In Jim’s case, he found debris packed in the transmission cross member the next day. Don’t stop inspecting until you’re positive you’re clear of any fire hazard.
A fire hazard isn’t limited to drive times, either. Once at your campsite, avoid parking over tall grasses. The catalytic converter can start a fire. (Just like parking over a pile of leaves in the city.)
How to minimize the fire hazards
Start with a thorough inspection and cleaning, of course. Increasing your vehicle’s ground clearance helps, too. A typical vehicle offers about 10-12 inches of clearance under its skid plate. Lifting an additional 3 to 4 inches makes a big difference. (“Honey, Tom says I need to lift the vehicle for the safety of you and the kids!”). Drill large holes in the skid plate, if you have the capability. (This is what Jim eventually did with his.) Or look for a replacement model designed that way. Much of debris should fall out as you’re driving along.
If and when a fire starts—whether under the frame or under the hood—you’ll want a chance to fight it. A good fire extinguisher is a must for every 4WD vehicle. (More on fire extinguishers at “Pack A Fire Extinguisher So You Don’t Get Burned.”) Two are even better: one up front and another in the back. Inspect those periodically to see that they’re still charged.
While I’m on the subject of fire extinguishers, I’d like to offer this thought. If someone walking down the street spots a fire, and a fire extinguisher on my vehicle is handy, I’d want him to use it. That’s what fire extinguishers are for: saving property and lives. I don’t care if I’m not the one helping out. Wouldn’t you be glad that a stranger grabbed the nearest tool to douse a fire involving some of your property?
Heck, I would even pay to recharge it. You get my point!
Fires, while rare, are real concerns while four wheeling. Vegetation packed in the undercarriage can go unnoticed until it builds to the point of combusting. Eliminate that hazard by thoroughly inspecting the underside of your vehicle when driving through vegetation. Also, make sure you have at least one properly rated fire extinguisher aboard at all times. These small steps can prevent disasters while off road.