You can add a CDL switch - the harness is there, you can get the switches from Slee, or modify a hazzard switch.
80 in ice & snow + question re CDL
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You can add a CDL switch - the harness is there, you can get the switches from Slee, or modify a hazzard switch.
No substitute, but from what I've read it's an impressive system - impressive in that it's very good at making you forget you don't have lockers, and very good comparied to some of the first traction control systems off road.
Can you read?
"H" (unlock): High Range, center differential unlocked
Use this for all types of driving on normal roads, from dry, hard-surfaced roads to wet, icy, or snow-covered roads. This position gives greater economy , quitest ride, least wear and better vehicle control.
"H" (lock): High Range, center differential locked
Use this for greater traction when you experience loss of power, such as wheel slipping, in the "H" (unlock) mode.
it says unlocked, "better vehicle control", I guess you can read into that whatever you like. Most people read that to mean you have better steering and braking control unlocked.
Your right on one, minut and meaningless point. It does not specifically say not to run Locked on pavement. It only says to use it when a wheel is slipping. As someone else said, if you have the power to make the tires spin on dry pavement, you must have more than just a blower on there.
So sorry that Toyota didn't predict somone like you who would read, "put the lock on when you spin tires" as "it doesn't say I can't run it on the hwy". That's a huge leap to make.
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Let's see
"H" (unlock): High Range, center differential unlocked
Use this for all types of driving on normal roads, from dry, hard-surfaced roads to wet, icy, or snow-covered roads. This position gives greater economy , quitest ride, least wear and BETTER VEHICLE CONTROL.
That pretty much says that unlocked has better vehicle control. iso-facto CDL has less vehicle control. Less vehicle control (using your word of compromise) certainly would be a compromise of steering ability wouldn't it.
And you still owe me an appology, I didn't make anything up, and don't like you saying I did.
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Thanks, I think I will do that, since it would be nice to run with CDL in places I want to fly through in 4H that are pretty straight, like wet muddy riverbeds, even though 'flying' would be 30mph...
I agree, by the way, that there is definite loss of turning control, even at crawl speeds, with CDL. Of course with front, rear and center locked, it's like steering a tank that has a mind of its own to stay straight on course. But that's fine if you're clawing near straight ahead out of something.
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I was thinking of you guys and this thread an hour ago. We're getting hammered by snow that fell on cold dry roads and immediately got worked into ice by passing traffic. The interstate skipped the snow step and went directly to ice - cars all over the place.
Just after it hit the worst stage, I had to head to pick up the kids from a nearby town, and I played with the CDL as I have the mod and dash switch. While driving straight, I engaged CDL, then made a lane change duplicating one I'd just made 50 yards before. The rear felt slightly loose, but did not prepare me for what happened next. The road curves to the right and the truck began to turn in, then understeered, then suddenly went into oversteer when I reacted by easing off the gas (bad move, but much more gently done than a typical driver that might completely drop the gas pedal). I frantically punched the CDL button as the rear sat about 25 degrees out, then slowly came back in as I used half of the oncoming lane. The CDL disengaged about the time the truck had stopped sliding, but it was interesting. About 10 seconds later I found out just how slick it was when I signaled a left turn onto the interstate and nearly did not make it.
Proceeded down the onramp with extreme caution and drove 5 miles back to town to get the kids at 35mph along with traffic at the same speed. Incredibly slick. Lots of cars off the road, etc.
So, a bit of experience from the trenches on what proved to be a very slippery day. I think the CDL is best left off for every day driving on slick stuff.
DougM
Just after it hit the worst stage, I had to head to pick up the kids from a nearby town, and I played with the CDL as I have the mod and dash switch. While driving straight, I engaged CDL, then made a lane change duplicating one I'd just made 50 yards before. The rear felt slightly loose, but did not prepare me for what happened next. The road curves to the right and the truck began to turn in, then understeered, then suddenly went into oversteer when I reacted by easing off the gas (bad move, but much more gently done than a typical driver that might completely drop the gas pedal). I frantically punched the CDL button as the rear sat about 25 degrees out, then slowly came back in as I used half of the oncoming lane. The CDL disengaged about the time the truck had stopped sliding, but it was interesting. About 10 seconds later I found out just how slick it was when I signaled a left turn onto the interstate and nearly did not make it.
Proceeded down the onramp with extreme caution and drove 5 miles back to town to get the kids at 35mph along with traffic at the same speed. Incredibly slick. Lots of cars off the road, etc.
So, a bit of experience from the trenches on what proved to be a very slippery day. I think the CDL is best left off for every day driving on slick stuff.
DougM
Hells bells, I know I'm going to regret this... but...
having just returned from being away, I just read the rest of this thread after my last post when I quoted my owner's manual verbatim. (well - my cruiser's manual - hehehe)
I will take the trouble to see if Emile's LX 470 owner's manual says anything worth adding to this discussion, as soon as I'm able, hopefully within the next few days.
That info was indeed verbatim.
Please DO NOT make me have to ask Emile for the big favor of scanning my manual, and showing me how to post it as an image. Please!
He often lurks here (80s tech) and in 100s tech.
I'm asking you to take my word for it that what I posted was, indeed, verbatim from the manual.
DISCLAIMER: I do not know Walking Eagle -- just as I do not know you, Sumotoy. To the best of my recollection, I have never "met" or interfaced with Walking Eage -- or with you, Sumotoy -- before this thread. I have ZERO motive to agree with him -- or to disagree with you, Sumotoy... other than the simple fact that my opinion concurs with Walking Eagle's.
And yes..... you may go right ahead and say that I'm nothing but a dumb old broad. But your having said it would not necessarily make it the truth.
having just returned from being away, I just read the rest of this thread after my last post when I quoted my owner's manual verbatim. (well - my cruiser's manual - hehehe)
I will take the trouble to see if Emile's LX 470 owner's manual says anything worth adding to this discussion, as soon as I'm able, hopefully within the next few days.
That info was indeed verbatim.
Please DO NOT make me have to ask Emile for the big favor of scanning my manual, and showing me how to post it as an image. Please!
He often lurks here (80s tech) and in 100s tech.
I'm asking you to take my word for it that what I posted was, indeed, verbatim from the manual.
DISCLAIMER: I do not know Walking Eagle -- just as I do not know you, Sumotoy. To the best of my recollection, I have never "met" or interfaced with Walking Eage -- or with you, Sumotoy -- before this thread. I have ZERO motive to agree with him -- or to disagree with you, Sumotoy... other than the simple fact that my opinion concurs with Walking Eagle's.
And yes..... you may go right ahead and say that I'm nothing but a dumb old broad. But your having said it would not necessarily make it the truth.
I have stated before that driving with the CDL engaged on dry pavement is SUMOTOYs opinion and sould be taken as such.
We all are entitled to our opinions and we try and keep tech so that folks can "politely" disagree.
My personal opinion is that you should not use the CDL on dry pavement.
We all are entitled to our opinions and we try and keep tech so that folks can "politely" disagree.
My personal opinion is that you should not use the CDL on dry pavement.
Grench
SILVER Star
I'm glad you're all right! I played with this on a snowy Sunday in a light industrial area (wide roads no traffic). That was scary enough. I'll bet that a down shifting slip effect on an interstate skating rink would have been downright unnerving.
Glad to hear you're OK!
And yes..... you may go right ahead and say that I'm nothing but a dumb old broad. But your having said it would not necessarily make it the truth.
I certainly wouldn't say that.
Really glad to hear it all worked out OK! Think about filing an NTSB report...
How fast were you going at the time, by the way? And how long did it take the CDL to disengage once you hit the switch again? Did you have to come off the gas to coax it to disengage?
Well, thanks for experimenting anyway!
I was traveling in the 30mph range - 35 zone with fresh snow. Seemed like it was only a couple seconds to get the lock light, and the same to disengage. Takes a couple seconds more for the ABS light to go off after disengagement, though.
DougM
DougM
Don't want to get into this argument, but feel it's important to give my experience.
I know from driving a lot in the snow on the road, in my 93 that CDL is less stable than un-locked. Maybe it's just me, but I played with this a LOT to come to this conclusion because I was wondering what was best myself.
reality was that with CDL, you encounter a lot more of the standard 4WD front end *push*. (go figure)
In turns it pushes... then you have to pay close attention and steer...steer...steer.... to make the corner while the truck is unstable.
normal, un-locked would just drive around the corner like there was no problem. I tried this numerous times, repeating on the same roads, on totally different days (different snow conditions)
*maybe*, like ABS, it's possible to turn and stop better than the *system*, but you really have to know what you're doing, and you really have to pay attention.
You don't want to *not* pay attention while driving in the snow, but the center diff unlocked is more stable and doesn't get you into that situation where you might need your ABS (which is no longer working with the CDL locked BTW...)
is it a perfect system? no.... but the problems are easier (IMO safer) to deal with than those that come up with the CDL locked.
I know from driving a lot in the snow on the road, in my 93 that CDL is less stable than un-locked. Maybe it's just me, but I played with this a LOT to come to this conclusion because I was wondering what was best myself.
reality was that with CDL, you encounter a lot more of the standard 4WD front end *push*. (go figure)
In turns it pushes... then you have to pay close attention and steer...steer...steer.... to make the corner while the truck is unstable.
normal, un-locked would just drive around the corner like there was no problem. I tried this numerous times, repeating on the same roads, on totally different days (different snow conditions)
*maybe*, like ABS, it's possible to turn and stop better than the *system*, but you really have to know what you're doing, and you really have to pay attention.
You don't want to *not* pay attention while driving in the snow, but the center diff unlocked is more stable and doesn't get you into that situation where you might need your ABS (which is no longer working with the CDL locked BTW...)
is it a perfect system? no.... but the problems are easier (IMO safer) to deal with than those that come up with the CDL locked.
nope, not just you, lots of people on here have come to the same conclusion. Even Toyota has.
...If at all. Doug, what tires were you running? From a vehicle *dynamics* standpoint, what happens during turns is that engine torque goes to the rear wheels, up to wheel spin, when torque then usually finds it's way back to 50/50 on low mu surfaces.
Regarding locking and unlocking.... I found this to be a very predictable event if you just blip the throttle just prior to wanting a *lock* or *unlock* event. What this does on slick surfaces is gives a quick spin up of the slower driveshaft, which then allows the unlock to happen. Dog clutches are designed to be no load devices, specifically they are looking for equal rotation.
I'd be intrigued to hear the comparison to unlocked CDL in the exact same spot under the same conditions. Your instinct to turn off the CDL seems counterintuitive to the conditions under which most folks *lock* the center diff.
I messed around with the diffs yesterday coming thru indiana and OH. I found the CDL to be much more stable, with predictable understeer. I can certainly think of instances where too much torque to the rear wheels will make it step out in a turn, but if the engine torque is there, it's not on the steering wheels.
During my event at the Center for Driving Sciences next week, I'll put up some video comparisons of CDL -on vs off in low mu conditions. I find these discussions interesting in terms of learning folks 'comfort zones' regarding vehicle dynamics.
ST
Thanks Doug, I find that my lockers take a few seconds to disengage too, and was wondering if there is a problem, or if this is normal activity...
Oops, just read SumoToy's response, and this makes sense: I'm probably feeling a delay because I drop off the throttle and it waits for the faster side to slow down... I'll have to try punching it for a second to speed up the slow side instead, although this will feel counterintuitive to me, that is punching in more spin potential when I am trying to regain tighter control.
In terms of psychology of troubleshooting, I probably do it the same way as Doug -he changed something that resulted in an undesirable situation, so the first thing to do is put it back the way it was before the problem and work from there... didn't seem counterintuitive to me. Unless one thinks that lockers give better control in all situations...
I did a lot of experimenting with this on the audis at Steamboat (vacuum operated, but same style dog clutch). I could predict within 10 feet - an unlock and a lock event with a quick throttle blip. I ran a ice rallycross using this method for the rear diff - center always locked. 10 feet before a turn, lift off brakes, hit CDL off, blip throttle, disengaged CDL, back on brakes. Then, at apex, hit CDL on, blip throttle, hit gas hard. Worked great! I've tried this with the 80 CDL swich, it works the same. Remember, the motor has a spring tension load on the dog clutch, it's just waiting for no-load equal driveshaft rotation. Hence the warning not to engage while wheels are slipping.
Specific to low mu, I think the CDL on is going to give better control - that's even what most folks here agree with.... In an open diff, 50% of the power goes to the front wheels all the time. So, in the same turn as Doug described, you'd have more torque load on the front wheels that are trying to steer in a very low traction event. Since I wasn't sitting in the seat while doug had his event, I attempted to just describe how axle torque allocation differs from an open diff in a turn. A locked CDL can cause an oversteer moment, up to wheelspin, then you are back to understeer again. In an open diff, you will have understeer all the time. But, if you also have 50% engine torque at the steering wheels, life could get really ugly as well. The big problem with locked CDL's is folks tend to lift throttle as soon as they feel the back end stepping out. Which can cause LTO (lift throttle oversteer) -sounds like what Doug got - which can really cause one to 'feel' things are getting worse.
IME, the 80 is one of the most neutral and predictable chassis with CDL locked. You can force a turn moment of oversteer in some cases (I found this to be very rare at Steamboat last year), but IMO as a rule, the 80 chassis wants to just drift out. As one well trained in the "scandinavian flick" it's really tough to get the 80 to really swing tail around with CDL -on. I'll be working on it again next week!
ST
If the transfercase is locked, the driveshafts are going the same speed, so there is no slower driveshaft.
Maybe you should just speak for yourself?
