By Jim Kerr
Saskatoon, Saskatchewan – Slippery roads, tons of snow and poor visibility have made driving this winter especially challenging. Vehicle rollovers have been frequent as drivers attempt to stay out of the ditch. If a vehicle is out of control and you try to steer it back onto the road quickly when deep snow is pulling the vehicle into the ditch, you stand a good chance of rolling. The vehicle slides sideways, the tires dig into the snow and BANG – over you go.
The right driving techniques will help prevent these rollovers. When the vehicle is being pulled into the ditch, steer it there unless you need to avoid hitting someone else. You will probably get stuck, but that is better than rolling a vehicle and possibly getting injured. What drivers really want is to avoid rolling over or getting stuck in the ditch in the first place. To do this, you need to maintain control of your vehicle and the suspension plays an important part in helping you maintain control.
Good tires are the best item you can put on your vehicle to maintain control. Summer tires may provide great traction on warm dry pavement, but winter tires work much better when temperatures drop below freezing or the pavement is icy or wet. Most new vehicles come with all season tires. These work most of the time, but when road conditions get bad they don’t grip nearly as well as winter tires.
Although all suspension components have to work together to provide vehicle control, shocks are probably the next most important suspension item. Shock absorbers may be separate units bolted between the vehicle body and suspension or they may be part of a strut assembly, depending on the type of suspension beneath your vehicle. Shocks prevent the vehicle from bouncing. When a tire hits a bump, even a small one, the tire is pushed up from the road. The springs and shocks allow the tire and suspension to quickly move up. Then the shock slowly (in relative terms) allows the tire back down to contact the road surface. If the shock allows the tire back down too fast, it bounces up again.
Bouncing tires spend very little time on the road, so their traction is poor and so is vehicle control. The standard test for worn shocks is to push down three or four times on each corner of the vehicle as if you were trying to bounce it. When you let go, the vehicle should settle to a stop within one up and down cycle. This test will detect very bad shocks, but shocks tend to wear most in the small range of suspension movement. Bouncing a vehicle up and down will check for wear overall, but your shock may be good in all areas except where it moves the most. If you notice your vehicle feels kind of mushy or you have to correct the steering to keep the vehicle going in the correct direction every time you go over a bump or dip in the road, then you probably need new shocks.
Shocks and struts come in standard, heavy duty and gas-filled models. Gas-filled shocks pressurize the oil in the shock so it doesn’t foam on bumpy roads, so gas-filled shocks provide the best control. If you are tight on cash (and who isn’t) go at least for the heavy-duty models. They cost very little more and provide much better damping.
Sway bars, spring rates, suspension bushing elasticity and control arm angles all contribute to vehicle handling. Performance enthusiasts will often change these items to improve handling for specific applications, but this is beyond the needs for most drivers. Getting an alignment done is the next step to ensuring your vehicle will handle properly. Four-wheel alignments are best for any vehicle on the road. The suspension should keep the wheels and tires sitting straight up and down and pointed straight ahead at all times for optimum handling. To do this, the suspension is adjusted so the tires are close to vertical and straight ahead at rest. If the tires are pointed to one side, or the angle on each tire isn’t close to the same, it can cause the vehicle to handle poorly. A wheel alignment does more than just prevent the tires from wearing out too fast. It affects handling characteristics too.
Good handling vehicles are more relaxing to drive, fun to drive and safer too. Preventative maintenance will keep your vehicle handling well and hopefully out of the ditch.