Disable ABS for Winter Driving

[mrsalty]

How did we all get along before ABS????

aamiggia,
Not to antagonize anyone here, but............http://sleeoffroad.com/technical/tz_cdl_pin7mod.htm
I have driven in the snow/ice (Colorado)much longer than I have owned any ABS vehicles. My ABS is disabled, and frankly I prefer that 'feel' (in addition to having a CDL on the fly). I am sure others like the ABS 'feel'. Make the decision based on what you think, not what others believe. Remember, this forum is an amazing resource for technical knowledge. Just make sure you differentiate fact from "OPINION".

My .02

Chris

94 FZJ80 138K 2.5 OME CDL Pin 7 mod 285's DD

 

[Koffer]

ok heres the stupid simple way to do it . Lock the center diff lock switch take it up to 40mph and the then turn off the difflock switch and the ABS has been disabled unit the key is turned off .

 

[aamiggia]

Thanks Koffer, that's exactly what I needed to know.

My old Prelude would switch off the ABS if you drove for a minute with the parking brake clicked up just enough to turn the dash light on.

 

[IdahoDoug]

Aamiga sed:

"I think that it's a known fact that ABS is not designed for snow & ice. A competent driver (which my wife is) can easily stop better in snow than the best ABS system. Threshold Braking will do wonders in the snow. The only thing that ABS does well is preventing the back end from locking up and spinning the vehicle. "

Just to clarify here, I flatly disagree with the first sentence - that is absolute blather. ABS was specifically designed to help deal with low friction surfaces.

I'll also disagree that your wife can outperform an ABS vehicle. Yes, in a matched event where she or any other talented driver is aware they're in a competition, etc the system can be beat. But that's not real world at all. I've done testing on artificial ice with talented drivers that were presented with a sudden obstacle and the ABS kicks their ass. THAT's what ABS is for - the 'holey crap this is a sheet of ice and there are cars stopped' or 'aaah there's a deer stepping into the road on this heavily crowned snowy road with ditches on both sides' type of thing. I can say with reasonable authority that you are way better off with ABS in the real world where you go from messing with the radio to needing max controlled braking on snow or ice.

And of course I'll disagree with the last sentance. ABS also prevents the fronts from locking up and causing you to understeer in to a ditch on a crowned road, helps you maintain control when you steer half off the road while braking to get around something, etc. Myriad situations.

Anectodally, in the testing we did, a good driver would discover the braking threshold by briefly locking the brakes then backing off until they unlocked and then squeeze back down. That's the only way to know where the threshold was. In our measuring, they gave up most of the braking distance from that required cycle that ABS uses - something like 60%. And these were trained subjects because we wanted a best case scenario. These same people could kick the ABS' butt if we simply said "drive at 60 to this cone and then get the car stopped as fast as you can" which is what you're saying when you claim your wife can outperform ABS. I agree. But life isn't a pair of cones - it's distractions, other traffic doing unexpected things, animals, ice patches where there was none an hour ago, crowned roads, and cell phones.

So, yes ABS can be beat by a talented driver who knows he or she is doing a comparison, and yes there are surfaces and speeds you can stop faster simply by locking the tires. But in the real world where the unexpected happens this simply isn't good logic. Get winter tires as John notes, and learn to stomp the brakes and steer into your choice of paths.

DougM

 

[aamiggia]

Doug, did you just refer to my wife as "a pair of cones"? J/K

Seriously though, I did mention,

I don't doubt the stability, but if you have to stop and have no where to go... Guess what? You have to stop.

Unfortunately when city driving in gridlock your only option is to stop in the least amount on distance. Not much unexpected happens when you're crawling along the highway, until you have to stop suddenly and swerving is not an option.

As I said,

a competent driver (which my wife is) can easily stop better in snow than the best ABS system

I should clarify this statement by defining "stop better" --> To stop in the shortest distance in snow & ice.

 

[Safado]

I have my own opinion, but I'll mention only this.

You might want to check with your insurance carrier as well. Whether or not ABS will help you in an accident can be debated depending on each accident. But whether or not your insurance company will pay out if/when your in an accident and your ABS was deliberately disabled...I think it's a pretty fair bet they won't. Wish you the best and a safe snow season.

 

[CreeperSleeper]

I have my own opinion, but I'll mention only this.

You might want to check with your insurance carrier as well. Whether or not ABS will help you in an accident can be debated depending on each accident. But whether or not your insurance company will pay out if/when your in an accident and your ABS was deliberately disabled...I think it's a pretty fair bet they won't. Wish you the best and a safe snow season.

As an insurance agent I agree with Safado. Most insurance companies now days are looking for any excuse possible not to pay a claim, so why would you give them an excuse?

 

[John E Davies]

I admit the tires are stock LTX m&s and "All Season" tires are for all season in the Southern US. They do not handle snow or ice at all.

I tried a set of oem LTX tires in the snow... and because of that I am now runnng Yokohama Geolander I/T+ snow tires.

I'm not going to argue the merits of ABS, but I am 95% positive that if you put your wife onto a good set of pure snow tires this winter you will no longer be talking about disabling the system.... and she will be a heck of a lot safer in traffic.

John Davies

 

[Bear80]

michelin truck tires suck in slick conditions PERIOD. Get them off the truck and a better set of snow tires. I've owend several michelin tires between my truck and 4runner. I have spun the rear end around on both of them excessively with Michelins. Michelin's are good tires, last forever but are they worth the chance of losing it on a slick road, HELL NO. Just my .02

 

[IdahoDoug]

Hey, I get to disagree AGAIN. Bear, the Michelin truck tires I have on my truck will stop faster on glare ice than traditional studded snow tires. They'll also corner better on ice and snow, accelerate faster, and even handle, stop and grip better on dry or wet roads.

The punch line? They're Michelin winter truck tires. Arctic Alpin 4X4 tires to be specific.....<grin>

DougM

 

[IdahoDoug]

And one more thing. This is an excellent ABS system. When it came out in 1993, it was the only system on the market that could operate in 4 wheel drive. Other systems were either rear wheel antilock only (RWAL) or the truck's ABS shut off and illuminated a warning light when shifted to 4 wheel drive. It is also a 4 channel 4 sensor system and even today there are a lot of 3 channel 3 sensor systems (use a single sensor for both rear wheels). Finally, it has a higher cycle rate than most systems of its day. So, it's a good system and it does sound like a lack of winter tires are your problem.

DougM (Mr. Disagreeable to you)....

 

[firetruck41]

I thought it was 3 channel? Either way it works great for me in limited snow and more frequently, black ice and frost covered roads. It's easy to threshold brake on dry pavement, not so easy when within several feet of wheel travel you have dry pavement, ice, and water, while it is starting to snow . If you choose to disable the ABS don't be shy to report any minor rear ender accidents you may cause

To each his own, but if you're behind me please turn the ABS on for just a minute

 

[LandyLover]

Let me chime in here. FWIW, I have done testing in a snowy parking lot with no obstacles around. There is no doubt I can beat ABS in a controlled (ie. predictable) situation. However, as IdahoDoug points out, real life is not predictable.

If you really are redisent in using ABS on a snowy or icy day, use your CDL in High range to get around. You can always slam it into 2nd or 1st, depending on your road speed, to slow you down in an emergency (if you can react that fast, which you probably cant).

On another note, with CDL on, Im sure the rapid loading/unloading of your axles as your tires get grip differentially (due to traction differences at each wheel) wreaks havoc on your center diff.

Cheers.

 

[IdahoDoug]

Man, I'm going to get elevated to 'Sir Disagreeable' before this thread is over!

Landy sed:

"If you really are redisent in using ABS on a snowy or icy day, use your CDL in High range to get around. You can always slam it into 2nd or 1st, depending on your road speed, to slow you down in an emergency (if you can react that fast, which you probably cant)."

Absolutely freakin' unbelievably WRONG thing to do. Slamming the tranny into a lower gear gets you one (count 'em - 1) level of braking that you cannot adjust. If it's greater braking than the snow/ice will permit you're sliding out of control and cannot instantly relieve the force like lifting off a brake. You have ZERO (count em) modulation ability here. It is absolutely ludicrous to do this instead of using a system that was designed to provide instantly variable amounts of brake force to each tire called your braking system - ESPECIALLY IN AN EMERGENCY!

Not to mention that brake application is near instantaneous by comparison. Reaching for, shifting, and finally getting the downshift would take at least a full second. At a mere 30mph you've just blown 44 feet or roughly two Suburban lengths to now find out if the tranny drag is going to put you into a slide, or be way less braking force than you need.

Sorry for the bandwidth but that is just cockamamie thinking. I think I need to drink less coffee............

DougM

 

[LandyLover]

IdahoDoug,
Its NOT something I would personally do because its not realistic in a life/death situation, however, it DOES work when you need to slow your self down. I attended a university on top of a mountain and where always snowed in winter, a road of 7% grade. I confidently geared down numerous times if I felt I was outdriving the conditions, but not when a deer ran in front of me. The truck never got squirrely. Gearing down slows you down safely, slowly. Reaction time, thinking of grabbing the shifter, grabbing the shifter, other variables takes away valuable time which makes this an UNREALISTIC option to a deer jumping in front of you, or a kid running out in front. However, if you see an accident 200 -300 feet ahead while driving on a slippery surface, having the engine assist slowing you down does good - no wheel lockup. The ABS (2nd level of braking) should, and is designed to kick in and take over if you panic as the engine helps slow you down. We're not talking of going to 2nd gear at 60 MPH, come on. Even dirtbikers gear down and come off the throttle on loose gravel/rock as they enter a corner because ANY other braking is too much risk.

Bottom line, I dont think the ABS is a liability. I have used it in snowy conditions and it works fine, but I always really like the braking predictability of my 60, which doesnt have it. I certainly would not disable it in my 80 series truck, but I would use the transmission to assist me in my main goal, to safely slow the vehicle down.


Cheers...

 

[aamiggia]

This is a very informative discussion.

Please let me recap, if I may. (This is all assuming winter conditions)

- ABS is excellent for stability and control to AVOID a sudden situation (deer or child)

- In loose gravel or deep snow locking the brakes (ie. no ABS) will stop in a shorter distance by creating a plowing effect.

- ABS will INCREASE the stopping distance in snow & ice

- It is not wise to disable ABS through the fuse under the hood. If you need to disable the ABS in a very select situation, the CDL will do the trick (It's a good excuse to buy one).

- Doug is Sir Disagreeable

 

[LandyLover]

Locking the brakes will only allow you to slide through an intersection. Do not lock your brakes. Threshold braking allows you to brake using maximum friction on your brakes without causing the brakes to lock. This is why gearing down if you see something come up ahead is a good idea, your engine asssist slowing you down without brake lockup, power divided front and back. Gearing should not be seen as an emergency manourver because it cant be used in an emergency - too much time for everything to react (you, the car, etc)

HTH

Later

 

[firetruck41]

- In loose gravel or deep snow locking the brakes (ie. no ABS) will stop in a shorter distance by creating a plowing effect.

I have a tough time with this one, it may be true in thick gravel, or on certain limited snowy surfaces (ie. dry snow on a dry road), but it is too general, I think there are many (probably most) situations where locking up in snow will not shorten your stopping distance, it may depend on the depth and consistency of the snow, and if the snow is on top of ice ABS will certainly give you advantge, IMHO.

The main thing is, chances are good you will need to stop very quickly, chances are much greater you will need to stop quickly and maintain control of the vehicle, that's where there is undisputable advantage for the ABS system in most real life situations.

 

[Scamper]

I'm not buyin this and have to agree with Doug on this issue.

First, the first thing I thought of when reading the initial post was "does your wife know how to use ABS brakes?". Not meant as an insult, but someone who's driven for years without ABS will instictively start to pulse the brake pedal when they hit a slippery patch. With ABS you just cram the pedal down.

Secondly, I think the vast majority of people that say they can brake better without ABS are fooling themselves. ABS gives you an immediate feedback that you're tires are not holding, whereas by the time you typically feel this without ABS, you're already sliding. I lived many years in Syracuse, NY where there are 364 days of snow, and 1 day of bad sledding, and once you learn how to use ABS, it beats standard brakes hands down. I would also question reports that people can brake better with standard brakes... How do you know that? The only way to really test that would be to take the same car/truck and go over the same spot under the same conditions with and without ABS active.

I will agree whole-heartedly that good winter tires make a hell of a difference, even on ice (I'm not talking about studded tires either--they make some really good winter tires these days). Before I'd start disabling safety features on a 6000 pound truck, I'd invest in some.

There...glad I got that off my chest

 

[IdahoDoug]

Landy,

I'm sure going to the university on a steep road taught you some things about slippery braking that will benefit you the rest of your life in snow driving. But you're absolutely wrong that downshifting is a good way to deal with slippery conditions. Let me explain just one reason.

When you downshift, you are getting a certain level of braking force - let's call it X. For the conditions you're on, X may be too much braking, or it may be way too little braking. Or it could be too much initially, then taper off to way too little as vehicle speed drops. But there's no way for you to change it - that means there is zero modulation.

On the other hand, you have a brake pedal that can instead exert braking force. With the brake pedal, you can brake at X, 1.2X, .80X and any level you would like and you can change (modulate) it several times a second if you wish to maximize your deceleration. So, for your theory of downshifting on slippery stuff to be valid, it would have to have the magical ability to go right to the correct level every time you did it on every surface at every speed you chose to do it, etc. This is clearly not the case, is it? Seriously, man - you are giving advice that is downright inaccurate at best and dangerous as well.

Here's something else to chew on. You've stated yourself many times that threshold braking is best (which I agree with) - so how do you square that with your downshift theory where the level of braking is quite random and may be WAY off the level needed for threshold braking? In point of fact, it would be absolute sheer coincidence for the level of braking from downshifting to be threshold braking. Threshold braking requires continuous adjustment of the pedal pressure as the vehicle speed changes and the surface changes. So your method can't do threshold braking by definition. So which is it - threshold braking is best, or downshifting is best because I can tell you that you cannot use both. Were I you, I'd pick the former theory and give up on the latter.

I appreciate your input based on where you attended college. However, I'm telling you my viewpoint based upon years of involvement with vehicle design and engineering, as well as having been GM's Worldwide Powertrain Planner, and having participated personally in the design, execution and data analysis of performance evaluations for all manner of traction controls, ABS, and AWD on controlled artificial ice and real ice. I've been to ice driving school. And to top it all off, I once drove a Triumph Spitfire through a Michigan winter with an engine stuffed into it that doubled the horsepower!!!!!!!

For the love of Pete, man - downshifting on ice or any slippery surface to slow the car instead of using the brakes is a bad strategy to use.

Sir Disagreeable