A lot of people everywhere now drive all wheel or four wheel drive vehicles. The half ton crew cab four-by-four is probably the car of choice. We happen to live in an area where it is a lot more likely that these vehicles will be used off road especially during hunting season.
The typical half ton four by four is not as equipped for off road use as it used to be. It is likely not designed as much for that type of use. Typically they can be equipped when purchased with option packages that make them a little more off roadish but the compromise always seems more shifted to on road use.
If you are considering some off road driving, for hunting or maybe getting some firewood remember just because it says 4 wheel drive somewhere on the inside or outside of the vehicle does not mean it is a mountain goat.
Unless your vehicle was specifically equipped it likely will not have any extra skid plates (metal plates that cover particularly delicate components on the underbody). A brush with a rock could quickly cause some serious damage. Aluminum oil pans are common now and they are a lot more brittle than stamped steel.
That suspension system that makes your rig handle like a race car on the highway is not designed to amble up a steep rutted rocky climb. A real off road suspension is made to articulate and have lots of travel. The wheels can therefore follow a more undulating surface. A highway suspension resists roll and articulation to provide that level planted feel on the road. It will have a hard time letting the wheels fall into ruts and climb up on rocks while still maintaining contact and traction.
When you are out in the woods looking for that perfect stand of firewood and a little bushwhacking is going to save you a lot of grunt work remember that those good mileage numbers you read about and may have experienced from your new truck are the result of aerodynamic improvements.
Aerodynamic improvements as a rule do not a good four-by-four make.
The front face of your truck or SUV probably is a lot closer to the ground then that old ugly beast you used to drive.
The bumper may be lower for safety reasons and lower than that will be an air dam of sorts (probably plastic). The low bumper and air dam wreak havoc with your approach angle.
The maximum approach angle in degrees is the slope angle you are able to start up from a horizontal plane without any part of the vehicle making contact with the ground.
Where your old Jeep could almost drive up a wall (well 45 degrees or so) your new pickup may not even get onto a 25 degree slope without tearing off that nice air dam.
What will be surprising when you do a little off roading with that new pickup is how quiet the interior is and how good your stereo sounds and how clean your shoes are (no hubs to get out and engage).
Remember when you get home, that just like your old four-by-four, it is time for some maintenance.
Wash off that mud and check those drivetrain fluids. If you went through any water make sure none of those fluids are contaminated.
Any water means it is time to change fluids.
Trail’s Ron Nutini is a licensed automotive technician and graduate of mechanical engineering from UBC. E-mail: nutechauto@telus.net
