Climbing a slippery grade in a big rig, is one of the most challenging situations you’ll run into when driving a truck for a living. Snow covered hills present a whole different driving scenario to a truck driver.
The goal is to get up and down the hill safely without losing traction. There are a few tricks to this which I use, which you also may find useful.
Watch the video version to learn how to drive a semi truck on a slippery hill.
5 Tricks to Maintaining Traction on a Grade
- Axle interlock engaged. When climbing a slippery grade, I like to have the axle interlock engaged. The interlock is engaged in order that all the drive wheels are in touch with the drive shaft and the gears. All the drive wheels are then engaged and working to pull you up the hill.
- Feather the fuel. Another thing I like to do is feather the fuel. Don’t give the truck too much fuel when you’re going up the hill because it could cause the wheels to spin. Just gradually give the truck some power.
- Keep the motor running closer to the top of its RPM range. That way, if the wheels do decide to spin a little bit, they can only spin a couple hundred RPM before they hit the limiter and then they can’t spin any faster, causing an even bigger problem for you.
If you’re down in the low RPM, slugging it up the hill and you hit a patch of ice, and all the sudden the wheels jump 600 or 700 RPM, then you’ll really spin the wheels. It’ll be all that much harder to redeem traction. Whereas if you’ve only spun, 200 RPM, you can just ease your foot off the throttle a little bit, bring the revs down, and the wheels will probably catch and you can ease back into it again.
- Don’t follow tracks. Another good practice when climbing a slippery grade is not to follow the tracks of other trucks up the hill. Chances are, the other trucks will have shined up the road as they climbed the hill. You’re much better off to cut your own trail for the best traction.
- Keep a little to the right shoulder. I like to do is climb a wee bit toward the right hand shoulder of the road. Chances are, there’s gravel on the right hand shoulder that will help give you a little more of a grip. You’ll then travel up the right hand side of your lane, hopefully with your right hand drive wheels in the gravel on the shoulder. Be careful not to get too far to the right. Just stay on the edge of the road try to find that bit of gravel on the shoulder. Sometimes that bit of traction, will be enough to make a difference between getting to the top of the hill or not.
How to Descend a Slippery, Snowy Hill
As far as going downhill on a slippery grade in bad weather, there’s only one secret to it. Slow. Go slow. Speed will just get you into trouble. Just creep down the hill like you’re walking down the hill.
Feather the brakes. Use the jake brake. But go down very slowly and you’ll won’t run into trouble. You’ll run into trouble if you’re going down too quickly and then have to compensate for your speed, over correct or over brake. You could then put the vehicle into a slide. If you’re creeping down the hill, you won’t get into that situation.
Braking should be gradual. You need to check the mirrors to make sure the trailer isn’t starting to jackknife. Use the jake brake as much as you’re able, making sure the unit stays straight. Do not travel too quickly. This is especially important on long mountain downgrades.
If the trailer is empty, it is lighter than the tractor, and it may start to jackknife if the tractor receives too much brake pressure.
When the trailer is loaded, it often weights twice as much or more than the tractor. Ging downhill, the trailer weight is pushing the lighter tractor.
If you must brake on a downgrade, do it when the truck is on a straight stretch of road. Don’t brake into a curve. The combination of the braking action and lateral movement at the same time on a slippery road, can be a hazard and cause the truck to slide. Do as much deceleration as possible when the truck is pointing straight down the hill.
Move slowly and steadily down the hill and you’ll arrive tractor first at the bottom, as you should.
How to Safely Climb a Slippery Grade in a Big Rig
- Engage the axle interlock. I’ve got all my wheels locked into helping out the grade. I’m going to use a combination of horse power plus momentum to get up the hill, without spinning my wheels. Now you can see that, thankfully, the sanders have been through here ahead of me. So we have some sand to drive on which creates some nice traction and that’s certainly a help.
- I feather the pedal, and don’t go into the corner too quickly. I’m keeping my RPM’s up a little higher than I normally do because I don’t want to wipe my feet then jump 700 RPM when she spins. If it’s going to spin, I only want it to climb a little bit, not climb a whole lot and become a major spin. So again, not too fast into the corners, you want to keep the momentum up.
Here’s a bit of a flat spot coming up and then a bit of a downgrade. I’ll be able to pick up another gear and improve my momentum, but still keeping in mind that control is the issue because I don’t want to slide off the road.
Here’s a bit of a downgrade but I can’t really take full advantage of it because of the corner in front of me. I don’t want to be going too quickly when I get to the corner.
- Keep your shifting to a minimum whenever possible, because it’s when you shift gears and let out the clutch that there’s the potential to spin the wheels as well, and you don’t want to be doing that.This particular grade has a stop sign at the top, which makes this even a little more tricky. If you encounter a road like that, don’t stop on the grade. You’ll have trouble getting your truck moving again. Stop at the top of the grade, once you’ve leveled out.
More Driver Skills:
- How to Back up a Big Rig Truck
- Scaling a Tractor Trailer
- Calculating Diesel Fuel Weight
- Sliding the 5th Wheel