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View Full Version : Snow sliding technique- throw it in reverse?


nakman
10-22-2013, 04:43 PM
On the Spooky Night Run there were a few guys who were employing a new technique to me, to reduce speed on steep icy descents. The feat was performed while the vehicle was essentially in a 4-wheel slide headed downhill on snow/ice, and was essentially locking up all 4 wheels, shifting to reverse, and giving it some gas to attempt to slow the vehicle down.

I was really surprised to hear guys were doing this, and without making it a big deal I did at least convey over the radio that "I'm not sure that's such a good idea." Seems to me like a good way to pop a pinion or birfield/CV (what if there was sudden traction on a locked axle), or just reduce friction even further to make the truck accelerate even faster.

But perhaps a revolution is at foot here and I'm just a late adopter, so would like to know if anyone else is using/recommending this method? :confused: discuss...

farnhamstj
10-22-2013, 04:57 PM
Are you meaning sliding down hill backwards on ice? then yes.

AimCOTaco
10-22-2013, 05:07 PM
I glad this came up as I was also questioning this technique after the run. I'm generally fascinated by all aspects of vehicle dynamics and this is not sitting right with me.

I'm familiar with shifting into reverse to maintain rolling control when sliding backwards but this is in fact a discussion of shifting into reverse while sliding forward.

To me it makes more sense to keep the wheels rolling and not slipping in the direction of travel in order to maintain steering ability (exactly why ABS helps with control). On that particular run after the first two slides I just left a ton of space to the next vehicle (like let him go until I could no longer see tail lights) and would keep rolling on the steep stuff while pulsing the brakes so that I could steer but did not slide as much.

I also wonder if the last vehicles would have encountered better trail conditions if this technique had not been used ahead of them? Either way this should be a great discussion.

MTSN
10-22-2013, 06:03 PM
On the group snow run back in the end of January, we encountered a couple spots where the trucks in front had packed down the snow pretty well and with the low temps caused patches of ice. At one point in the trail, several of the trucks (including me) had to get up momentup to go up a small hill, lost momentum and slid backwards at a considerable speed. I had almost made it to the top on one attempt but got hung up on a rock and had to reverse out to try again, and when I put it in reverse and tapped the gas I started careening out of control backwards down the hill at probably 10-15mph which was honestly terrifying.

I took it out of reverse, put it in neutral for a second, then put it in drive and gave it gas to slow my backward slide knowing there were trucks and people back there. I was worried it would cause driveline damage, but I was more worried about hitting someone. Perhaps it was due to the extremely slick conditions where the lack of traction didn't cause binding, but I noticed no binding/banging/clanking or anything when I did it. It definitely did significantly slow my backwards slide and maybe prevented a collision.

My girlfriend looked at me afterwards and said she had never seen me that scared or move my feet and hands around the wheel and shifter so fast before!

Edit: here's a pic from the run

Shotshell
10-22-2013, 06:12 PM
OK.
So, I'm the one who mentioned this that night. And I did use it, as well as at least one other person who used it to try and not rearend me.

I DO NOT RECOMMEND USING THIS TACTIC, except in extreme circumstances and only on VERY slippery surfaces, I.E. Ice/compacted snow or really slippery mud.

That night, I got to sliding pretty fast and right at a tree. I didn't even think about it, I just did it, and I stopped just shy of the tree. I used it later to stop after having picked up considerable speed trying to get away from an incoming FJ.

OBVIOUSLY this should only ever be done when ALL FOUR tires are locked up and NOT turning. And then you floor it, and then let off the brake, to produce initial backwards spin on the ice, thus giving uphill force on the vehicle while minimizing stress to your moving parts.

That being said, this obviously does put unwanted stress on your moving parts involved. And outside of a really slippery circumstance, should never be executed.

As far as it perpetuating the slippery surface for the later rigs coming down the hill... I doubt it, as there wasn't much snow left on the areas where I executed this move. I pretty much dug it out to the mud below.

That's just my $0.02 I know many of you will probably disagree with this, and think me foolish for using it. But, I made it out in one piece without hitting trees or other rigs. Seems legit to me. Hopefully I'll never have to use it again.
Thinking back about 7 years ago, I wish I had used this technique one rainy muddy night. Might have prevented me from hitting that oak tree at the bottom of a hill. Who's to know.

Bottom line: To each his own.

(side note) If this does get adopted for use in emergency situations, I call dibs on it. It will be know from now on as "Pulling a Shotshell.":hill::thumb:

JadeRunner
10-22-2013, 07:18 PM
I can't say I've done that before. I suppose if you could get just the right amount of traction and a little "dig" it would help you. And if things were happening slow enough. The risk being as Tim said if you caught a rock or sudden traction it could break something.

nakman
10-22-2013, 07:38 PM
Travis you just reminded me that I've done this before, but years ago and in a manual truck. Was sliding backwards, and I shoved it into 1st then dumped the clutch and peeled out forwards. Not sure if it did anything though, as it was only about a 5' long event. I still think it actually lowers friction to intruduce the other direction of wheel travel.. I also will sometimes experiment with neutral as opposed to any gear when on something steep, just so I'm not fighting the engine. But then once things lock up, I slam it down to L and start pumpin...

I also just remembered my sweet move from high school- I had a 4wd Chevy Luv, and you had to be at a "full stop" to switch from 2wd to 4wd, or from 4wd to 4LO. So I'd get up some speed, slam on the brakes, put the clutch in and shift on the fly... had it down pretty good too :hill: Was especially useful when it was snowy coming down Berthoud pass or something, I knew by Empire it'd be down to pavement again so last snowy corner I'd rock the 4-to-2 move, so I could drive home in 2wd and not have to stop. Not exactly relevant here, just thought that was a funny memory... I'm going to make sure my son gets a manual transfer case in HS.

Fishy
10-22-2013, 07:47 PM
I actually started down some of the descents the other night in reverse. There was no question where the traction was, or wasn't. Ice looks like ice, you can't miss it. I also kept 1 foot on the gas, 1 foot on the brake and my hand on the E-brake.

Clearly, this is a last resort and a sketchy technique that claimed MtnAddict's ring gear on the way down. I was more concerned with getting sideways and rolling over with my wife and kids in the truck. I can't stress enough how out of control that ice filled descent was. There was no/none/zero traction on the way down.

Once you get to a certain speed, staying on a tight trail like that was out of the question. If you're on full ice like we were, the reverse/brake/gas/e brake can help you at least stay straight.

60wag
10-22-2013, 08:35 PM
I don't buy the ebrake thing. If the truck is in 4wd and the center diff is locked, when you apply the ebrake, (rear drums) you effectively brake both the front and rear drive shafts applying braking force to all 4 wheels. On a 2wd car, yeah the ebrake will add drag in the back and might straighten things out a bit but not on a 4wd vehicle.

I missed the the sled run down the icy hill due to the rec' that we not follow. I'm glad that the suggestion was made and that we chose to follow it. I'm undecided on the reverse technique. I can see where it could make the tire claw through some of the packed snow/ice and find a bit of traction that an braked wheel wouldn't. Unfortunately the differentials aren't tough enough to make this a choice without consequences.

mikeyhcrana
10-23-2013, 09:24 AM
First of all, with my automatic this would not work for me. Even in my 5-speed 4Runner, I would not do that. E-brake is the most effective technique IMO, and it's what saved us. Here's why, I think.

I used to race dirt track modifieds. They don't use much front brake because if your front locks up, you can't steer. On the other hand, you poke the rear brakes, weight transfers forward, and you can steer. Same thing here where it is so slippery, especially going downhill. Slightly setting the E-brake loads the rear brakes so even when you start poking or pumping the brakes, the weight transfers forward without locking the fronts.

Some people say hit this gas when you are sliding downhill. That transfers weight to the back and although you could steer again because the fronts aren't locked, you have to be able to stop the momentum you are gaining soon or the problem is worse. That would have been bad for this Spooky Night Run because nobody knew when they could stop. Probably a good technique for more of a Red Cone situation where all that matters is not sliding off the side.

Going into reverse while moving mimics the correct weight transfer but it's harsh, and out of control. Reverse is for rotating the tires in reverse, you don't want that you just want to use the rear tires to transfer weight to the front without locking the front so you can steer. E-brake does this precisely, predictably and in control. You could even lock the rears and drift down the hills and still be in control because you can steer and modulate the rear handbrake. Maintaining control is priority.

This is my hypothesis, I have no proof, just my opinion. And like the football commercial, it's only weird if it doesn't work. Everybody got the job done that night. In situations like that you can't hesitate and you must trust your instincts, if reverse saved you, I believe you made the right call.

mikeyhcrana
10-23-2013, 10:06 AM
Was the 4runner who broke doing this, that night?

subzali
10-23-2013, 10:06 AM
This is why I'm still a fan of chains.

nakman
10-23-2013, 10:24 AM
Good points Mike. And yeah, it was a 100 not a Runner but yes, I do believe the front diff broke while using this method. We can speculate up and down if that was the root cause, or it was already worn, or it's the weaker 2 pinion known issue design anyway... but alas the load it saw on Saturday night would appear to be the proverbial last straw.

Matt hasn't been mentioned yet, but Seldom Seen was running chains in the back- he said it felt solid the whole way down, almost no wheel slip at all. Think he was about 4 or 5 in line, out of 11.

Fishy
10-23-2013, 11:47 AM
I would have liked to try the chains. It's something I've considered for my truck (at least having them available to put on). But, I need to run wide spacers in order to make them fit with the 35s. Even with the body lift, I still touch the inner fenders on hard compression.

Josh has the 4 pinion diff, like I did. In this case and in mine when I broke, it wasn't the spider gears but the ring gear that broke. The carrier that the ring gear bolts to deflects/flexes just enough and the pinion jumps and breaks ring gear teeth. I got a good look at mine when I took it apart. Obviously, this may have happened on the reverse descent, or it could have happened during one of the climbs. A spinning wheel that suddenly grabs traction sends a shock load through the system and in this case found a weak link.

I'm convinced that as the 4-pinion type 100's get used/wheeled/worn more, they will break at the same rate as the 2-pinion. The carrier of the ARB or TJM (what I have) is much stronger/ridged than the OEM carrier and doesn't allow for that deflection. Plus, most of the time the person is re-gearing or at least installing new gears at the time of the locker install and more preload is set-up. That also reduces the chance of the pinion and ring gear separating.

You guys who have done this as PM on your 100 did it right. I had to learn the hard way. Nothing motivates learning something new like having to spending money. :wrench:

Fishy
10-23-2013, 11:58 AM
Here's a picture of mine.

I think the first break caused some loose teeth to bind again and break a few more spots. Just like in Josh's case, I could still drive and only felt a very slight clunk. It wasn't until I stopped and removed the driveshaft/flanges and spun the tail flange of the diff was I sure of what happened.

http://i1216.photobucket.com/albums/dd364/coflytyer/IMG_4050_zps28267548.jpg (http://s1216.photobucket.com/user/coflytyer/media/IMG_4050_zps28267548.jpg.html)

http://i1216.photobucket.com/albums/dd364/coflytyer/IMG_4055_zpsdb863738.jpg (http://s1216.photobucket.com/user/coflytyer/media/IMG_4055_zpsdb863738.jpg.html)

AHorseThief
10-23-2013, 01:19 PM
This is why I'm still a fan of chains.

Agree completely. I don't go winter wheeling without them.

AxleIke
10-23-2013, 06:17 PM
The action of shifting from forward to reverse with the wheels stopped will no more shock the driveline than reversing normally from a dead stop.

The larger issue here is spinning tires, as fishy pointed out. A few things to keep in mind:

Diffs are stronger in one direction than the other. Depending on your pinion orientation, you may have a stronger diff moving forward, or a stronger diff moving backwards. When you drive on the coast side of the gear, the diff has less resistance to grenading.

Second, with unlocked diffs, you are likely spinning one wheel. Not only is that wheel spinning twice as fast as the ring gear, it is getting 100% of the torque supplied by your front output shaft of your transfercase (assuming center diff locked, or traditional transfercase) where in normal operation, it sees 50%. That is more of a concern for axles, than diffs, but it is a common problem for open diff trucks.

Either way, I think the message is: avoid spinning tires if you can. It is necessary sometimes, but if you can avoid doing it, so much the better. Parts have memory. The more you stress something the more likely it is to fail the next time. By minimizing situations where you are torque loading one side of the diff or the other, the more likely things will hold up when you absolutely have to.

And, body work is usually more expensive than driveline work. Not always, but you can make junkyard driveline parts work more easily than junkyard body parts, unless multi-colored trucks appeal to you :D

AxleIke
10-23-2013, 06:18 PM
Agree completely. I don't go winter wheeling without them.

They are good to have, but as with all things, they have situations (like the one above) where they are good, and situations where they are bad (deep snow, snow bashing), where flotation is more important than maximum traction.

AimCOTaco
10-24-2013, 11:42 AM
I'll definitely agree that anyone who completed the run did great and that chains were king! It really is amazing that there was no real body damage on any of the trucks that descended and that says a lot about everyone's technique and really highlights the fact that there is no one right way to get the job done.

As I read the experiences of guys "pulling a shotshell" I guess I could see a few cases where as a last resort (like a collision, cliff of doom, or insane deep powder) that it could be an option for me.

I still think that a tire rolling in the correct direction is the best way to maintain good steering control which is key for obstacle avoidance in general.

I have not done a lot of winter wheeling the last couple of years but I'm definitely reminded that a good set of quickly deployed chains would have been the safest and most prudent way to approach this descent (another item for my list). This is probably even more the case after other vehicles have polished up the slick spots.

Fishy, speaking of chains, I'm glad you mention the challenges of using them with 35's on the 100. I had never considered chain fit or heard it discussed before with regard to 35's on the 100. I'm trying to keep myself talked out of going down that road for now so this is a great point for me. I like the idea of 35's but I really need to focus on a number of other mods first so anything that keeps me from jumping into 35's is a good thing (at least for now).

As expected this is a great discussion, I love a good tech debate :cheers:

subzali
10-24-2013, 12:10 PM
Chain fit is a huge consideration. I don't mind having chains on my 40 because if they rub (which they do) then meh - my tub isn't perfect anyway. But I have hesitated going to larger tires because without more lift the rubbing would be even worse.

Chains on any wagon is going to be difficult. Especially if the bare tire rubs at full compression the way it sits now.

Fishy
10-24-2013, 12:19 PM
I think the only way for me to run chains would be 1.5" spacers, which I was kinda trying to avoid. Although Christo's new ones have me interested. http://www.sleeoffroad.com/products/products_wheelspacers_main.htm

I've already done a 1" Body Lift, which caused me to lower the radiator by 1" and spend a day figuring out a .5" steering spacer and firewall mods. There is simply no way to raise the body anymore without some serious linkage/line issues.

What is everyone using for chains? Obviously I need the smallest/lowest profile chain I can get. Maybe I'll see what I can do to make them fit and work.

AimCOTaco
10-24-2013, 12:48 PM
I've always wanted a set of the RUD chains you can get from Safari Ltd. They are low profile and can be installed without moving at all so you could throw them on after you're stuck if need be. Definitely a cut above the cheap walmart stuff in quality, not sure where the prices are.
I've always put it off because they are very tire size specific and between two trucks and changing tire sizes I can't ever settle on a size to buy... that said, I think I need a set for the 285/75-16's currently on the LC as I think a set of like sized Duratracs are in her near future.

Fishy
10-24-2013, 01:07 PM
http://www.rudchain.com/

MTSN
10-24-2013, 02:17 PM
I kind of like these for off road:

http://www.tirechainsupply.com/product219.html

Fishy
10-24-2013, 10:38 PM
^Unfortunately, they wont work for me. Not only do they not have my size tire but judging from the picture, they add too much width.

AimCOTaco
10-25-2013, 08:20 AM
^Unfortunately, they wont work for me. Not only do they not have my size tire but judging from the picture, they add too much width.

Simple, 35's all summer, 33's w/chains for winter! It's only money right?

Speaking of chains it does look like 'tirechainsupply' has a diamond pattern that you can install without moving the truck. I think the diamonds would be a much smoother road ride if you needed them for that as there is always chain under your tire unlike that ladder style that rattles your teeth.

Looks like good chains cost real money to.

nuclearlemon
10-25-2013, 07:52 PM
Haven't read the whole thread yet, but gotta stop the "shot shell" thing now. Sorry,but this has been done for decades. Anyone who actually learned to drive in the Midwest learned this trick. I learned it when I was 16. I also learned how to e brake a turn in both rear and front wheel drive cars. I learned to shift the case :on ice and gear through corners. There's not really any new driving techniques out there

Shotshell
10-25-2013, 08:17 PM
Haven't read the whole thread yet, but gotta stop the "shot shell" thing now. Sorry,but this has been done for decades. Anyone who actually learned to drive in the Midwest learned this trick. I learned it when I was 16. I also learned how to e brake a turn in both rear and front wheel drive cars. I learned to shift the case :on ice and gear through corners. There's not really any new driving techniques out there

Ah man... :( *bubble = burst*

black95
10-26-2013, 07:59 AM
I would figure everyone here has at least once been sliding backwards down an icy hill and had to slap the tranny into drive and floor it. I have, and it saved my butt. I don't see where the opposite is any different. I say if you're running a tire size and combination that is large enough to break your drivetrain with just spinning your tires, then you're running on a thin line and its time to upgrade anyway. I agree with AxleIke and would much rather replace drivetrain parts than body work too.

I don't get the Ebrake thing at all. Seems like that would cause the rear end to try to pass you up on a downhill, much like having your proportioning valve adjusted too tight on the street.

Those who are saying to give it gas on a steep icy hill have obviously never been careening down an icy hill... the LAST thing you want is more speed. I was on a run and saw a Tacoma lock the brakes down a hill and pick up a significant amount of speed right into a pine tree... which proceeded to fold the ARB bumper over the hood, effectively sealing it shut so we couldn't get the fan out of the radiator. Dead rig. I came down nice and slow with my tire chains.

nuclearlemon
10-26-2013, 09:26 AM
Those who are saying to give it gas on a steep icy hill have obviously never been careening down an icy hill....

actually, if you're sliding and can feel your rear starting to break loose to pass, you do want to hit the gas to straighten the rig out and regain steering control

nuclearlemon
10-26-2013, 09:27 AM
Ah man... :( *bubble = burst*

sorry to burst your bubble :(

Fishy
10-26-2013, 11:42 AM
I think it's important to point out that "throwing" it in reverse and just mashing the gas is not what is being discussed here. I don't want anyone to get the wrong idea from the thread title. I learned to drive on the ice filled mountain roads of the Catskill Mountains. Even our driveway was long, steep, rutted and gravel.

Keeping the rear of the truck behind the front of the truck was my sole purpose during the SNR. Only once did I get slightly sideways and was able to come to a stop. On some of the other steep downhill sections getting sideways would have most likely ended in a rollover. I used reverse, brake, gas, e-brake and "Jebus take the wheel" to get down. The one thing we had going for us was the trail is dug out a lot and shaped like a luge hill, as long as you just banged the sides and didn't go out of the "bowl", you could essentially just careen off the sides until you regained control.

Being last in the line of 12 meant there was no more fresh snow to "grab" traction on. It had already been spun/slid on and turned to ice. Here is a bad picture from earlier this summer where I was climbing the area that we descended that night. I would consider this a wide spot in the trail.

Shotshell
10-26-2013, 07:15 PM
AH, I think I remember hitting that large rock on the way down, Stan. :thumb:

Shotshell
10-26-2013, 07:17 PM
sorry to burst your bubble :(

No, it's all good. :beer:
It was a long shot, but I thought I'd go for it.

nakman
10-26-2013, 09:27 PM
I don't want anyone to get the wrong idea from the thread title...

but a compelling headline makes for a much more entertaining discussion! :D

Caribou Sandstorm
10-27-2013, 06:55 PM
https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcR7Ks0ai11-ECWtLgsWhZMHCe8HMtQD-ZWxiVybGo7MHthGlI2-

RockRunner
10-27-2013, 10:36 PM
Haven't read the whole thread yet, but gotta stop the "shot shell" thing now. Sorry,but this has been done for decades. Anyone who actually learned to drive in the Midwest learned this trick. I learned it when I was 16. I also learned how to e brake a turn in both rear and front wheel drive cars. I learned to shift the case :on ice and gear through corners. There's not really any new driving techniques out there

You are right Ige, been doing it since '79 in a ford station wagon from there a very build Firebird and many other rigs. The thing I hated the most was the placement of the E brakes on the Toyota, next to the steering column. You could Steer the rear by just using the e brake only.

As for doing this down slippery hills, it takes practice and a soft touch. Practice in a parking lot when it is snow-covered and you can slowly master this "old" technique

AimCOTaco
10-28-2013, 08:05 AM
AH, I think I remember hitting that large rock on the way down, Stan. :thumb:

Yep, that rock stopped me for sure also, I like that rock. I distinctly remember seeing it and putting the driver front right into it for a quick pause, deep breath, and back to the action move.

MtnAddict
10-29-2013, 07:52 PM
I missed this thread somehow, but great read.
It was my diff that blew that night using the reverse technique.
Driving in snow/ice does take a little finesse, but as you gain speed and no traction, finesse is out the window, I just wanted to slow and stay on the trail. As Stan said I was using brake, e-brake and used the reverse a few times with light skinny pedal. This worked well until I was gaining too much speed on a downhill section and I think if I hadn't used reverse I would have ended up off the trail into a tree/rock with my wife and another passenger. Possibly rolling. I took the chance and "blew" it. Ha.
Good times though and again, thanks to all that helped get me rolling at the trail head.