Mountaineer01 previously posted:
"Wow glad everyone was safe! Do you mind me asking what happened? It doesn't look like much of a slope to flip a truck, but I'm sure you weren't expecting that to happen either so I would love to learn from your mistake
"
It was a pretty specific set of things that caused us to end up on our side despite going at a snails pace. Basically, I hit some really slick ice on about a 13% grade downhill and lost my rear tires. I then picked up speed due to the hill while going forward at an angle (think crab walking) and my front tires hit the side of the road and stopped moving. My rear was still on the ice though, so it kept its momentum and swung around giving us some fun new angular momentum that was apparently enough when combined with the couple inches of drop off to plop us on our side once the rear tire went off the road, leaving us on our side and facing the way we came from.
Hyper detailed illustration:
The takeaways are:
#1 DO NOT ENGINE BRAKE IN AN AUTOMATIC ON ICE. This is the #1 mistake I made. I was already going slow (I grew up in the midwest so I learned to respect ice and be careful), but I saw how steep the rest of the hill was (with a corner at the bottom as well) and was like "I'd really like to use my engine to help keep my speed down" thinking that would be less disruption to the tires, which is true to an extent but only if you're already in that gear. Because I downshifted, that sudden engine break broke my traction in a way that ABS couldn't compensate for (since there's no ABS in the transmission). In a manual you could rev match so that there is no disruption when downshifting, but I don't know if that is possible in an auto. I should have just used the brakes and let ABS do its job instead of trying to be fancy about how I kept my speed down.
#2 I should have had snow chains on. I had plenty of tread left on my tires and was in a 4x4 vehicle so i was in compliance with the colorado traction law, but compliance isnt everything. If I had them on me I would have stopped and put them on, and it may have saved me from the accident. Now law or no law, i'm having chains available in the truck at all times during the winter season.
#3 I should have just left it in 4x4 the whole time. There were patches of dry concrete between sections of pure ice, and everything in between (just based on how much sun a specific part of the road got). I was trying to have a bit of mechanical empathy and only engage 4x4 when it was real slippery. In reality, the drive train is plenty strong enough to handle a little bind in 4x4 (with the rear locker disengaged) on mixed surfaces. It will let out the tension next time it hits a slick spot. As long as you're not doing super sharp turns on bone dry concrete, you don't need to be going in and out of 4hi like I was. When I came over the hill and got into my predicament, I was in 2hi, not 4hi. It's possible that being in 4hi would have more evenly spread out the disruption of my mistake #1 (engine braking) but because I was in 2wd all of that deceleration force went into my rear tires, which is very likely why they lost traction
#4 I missed a turn and was on a much less maintained road. I should have been on CO 72 but I missed that turn and was onto side roads that hadn't been treated for ice yet. I should have found a safe space to turn around and get on the more maintained road.
Bittersweet new truck celebration
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