BlackHorse Posted March 1, 2007 Share Posted March 1, 2007 http://www.youtube.com/watch?v=dNrmUJ_aoWc I have to say, that's a truly crappy 4WD system. Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted March 1, 2007 Share Posted March 1, 2007 Cool music. And an explanation for that right front wheel However, once it does slip, recovery is difficult. Suppose that the left front wheel slips on an icy patch of road with a design that drives all four wheels. The slipping wheel will receive all of the power, causing it to spin twice as fast as desired, while the wheel on the other side stops moving. The average speed remains unchanged, and neither wheel gets any torque. A similar problem occurs between the front and rear axles via the center differential. The front left wheel receives all of the power, again doubling its speed while the rear wheels stop moving; again, the average speed is maintained. The available torque goes to zero, and the left front wheel actually turns four times as fast as it should be turning, preventing the other three wheels from turning. This problem can happen in both 2WD and 4WD vehicles http://en.wikipedia.org/wiki/All_wheel_drive Ford has used viscous coupling center diffs for something like 7 years now (ControlTrac 2 forward). These units prevent the exact issue you saw here: the seeming paradox that the wheel with no traction at all gets all the power. Quote Link to comment Share on other sites More sharing options...
ebritt Posted March 1, 2007 Share Posted March 1, 2007 Cool music. And an explanation for that right front wheel http://en.wikipedia.org/wiki/All_wheel_drive Ford has used viscous coupling center diffs for something like 7 years now (ControlTrac 2 forward). These units prevent the exact issue you saw here: the seeming paradox that the wheel with no traction at all gets all the power. My 04 explorer goes great in the snow. 4 wheel low and it will go anywhere. Quote Link to comment Share on other sites More sharing options...
retro-man Posted March 2, 2007 Share Posted March 2, 2007 (edited) It looked like he didn't have the 4WD even engaged until right at the end. You know, that bit about the way limited slip works....... I realized this just the other day when I was out in #2 son's '65 Mustang in some light snow: I hit a slick spot under acceleration, and I could sense one of the drive wheels slipping, but the car didn't fishtail at all - because the other one still had traction. In my T-Bird, when it slips, it slips. And it fishtails, with the engine doing it's electronic sputter and all. It's not a great feeling. I have memories of being able to pilot the '63 Galaxie of my youth just fine in snow, and even black ice, on street tires! I thought it might just be the superior coordination and reaction times (and boldness) of my youth, but it could be there were some superior driving attributes to that old technology. Edited March 2, 2007 by retro-man Quote Link to comment Share on other sites More sharing options...
NLPRacing Posted March 2, 2007 Share Posted March 2, 2007 My 04 explorer goes great in the snow. 4 wheel low and it will go anywhere. As long as the tranny and rear end stay together, right? Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted March 2, 2007 Share Posted March 2, 2007 It looked like he didn't have the 4WD even engaged until right at the end. It was engaged. The 4Runner is, under most conditions, RWD. The front wheels are spinning because the vehicle doesn't have a high quality AWD unit. Either the vehicle should have a true 4x system (as the Explorer and Expedition do) which locks all four wheels together, preventing one of the wheels from spinning freely, as in the video. Or the vehicle should have a viscous diff that will transfer power to other wheels once wheelspin occurs (Control Trac II, Haldex, 4Matic, 4Motion, etc.) This is not some kind of 'Fords are better' screed. This is Toyota using less than adequate technology because it's cheaper. Quote Link to comment Share on other sites More sharing options...
ebritt Posted March 2, 2007 Share Posted March 2, 2007 As long as the tranny and rear end stay together, right?I'm keeping ny fingers crossed.... Quote Link to comment Share on other sites More sharing options...
BlackHorse Posted March 2, 2007 Author Share Posted March 2, 2007 I have to agree 100% with Richard on this one. Toyota bills that AWD system in the 4 Runner as some kind marvel of modern off roading technology. It's clear in the video what was happening. It's not a good system. The driver had it in 4WD the entire time but the fancy technology kept delivering the torque to the wrong wheel. That little 4 inch high pile of snow whipped the 30+ thousand dollar 4 Runner and all its fancy off roading prowess. They should take the whole thing back to the drawing board and start over. Proof that when it comes to Toyota in many cases you really are just paying for the name. Also I should add that I'm a big fan of the Subaru stuff and that's what the man filiming the stuck 4 Runner was driving. Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted March 2, 2007 Share Posted March 2, 2007 Actually, it's not fancy technology. It's the most obsolete technology in the industry. Quote Link to comment Share on other sites More sharing options...
bec5150 Posted March 3, 2007 Share Posted March 3, 2007 (edited) Looks to me like you all saw what you wanted to see. But let's look at it with the anti Toyota glasses off. First of all, he has an open diff in front and in back. Many 4wd's come this way. The best you can do in most cases is a limited slip in the back and since both rear tires were sitting on ice, that wouldn't have done you any good. In only the most rugged off road set up do you have a locking front differential. Second, the video showed no less than four times he had it out of there and right when the vehicle was just getting ready to come out he hit the brakes, indicated by the brake lights and the tires not spinning. Third, he never did the "rocking" procedure that ALL of us Northerners know. So in a nutshell, there are two factors here: 1. Open diffs front and back, the same exact setup that 95% of all 4wd's run. 2. An incompetent driver. Edited March 3, 2007 by bec5150 Quote Link to comment Share on other sites More sharing options...
Hemiman Posted March 3, 2007 Share Posted March 3, 2007 (edited) Looks to me like you all saw what you wanted to see. But let's look at it with the anti Toyota glasses off. First of all, he has an open diff in front and in back. Many 4wd's come this way. The best you can do in most cases is a limited slip in the back and since both rear tires were sitting on ice, that wouldn't have done you any good. In only the most rugged off road set up do you have a locking front differential. Second, the video showed no less than four times he had it out of there and right when the vehicle was just getting ready to come out he hit the brakes, indicated by the brake lights and the tires not spinning. Third, he never did the "rocking" procedure that ALL of us Northerners know. So in a nutshell, there are two factors here: 1. Open diffs front and back, the same exact setup that 95% of all 4wd's run. 2. An incompetent driver. Driver was incompetent. I discussed just this situatoin on this board a while back. He should have been able to go from 1WD to 2WD by putting the X-fer case in low range. That should have locked the center diff. Not sure of how the Toyota system works, but this is pretty standard for the industry. Edited March 3, 2007 by Hemiman Quote Link to comment Share on other sites More sharing options...
Paul Selby Posted March 3, 2007 Share Posted March 3, 2007 Like others have said the driver was the problem. Along with rocking he need to keep the front wheels straight but this guy never did that, he kept turning the front wheels. Here's one I'm sure Ford doesn't want people to see. Quote Link to comment Share on other sites More sharing options...
bec5150 Posted March 3, 2007 Share Posted March 3, 2007 The center diff is locked from the time it's put in 4wd. It's the "side to side" locking that wasn't happening and doesn't happen in all but the most serious off road equipment. So he was spinning one front wheel and one back wheel. Even in a "limited slip" rear axle, if you have one wheel on good traction and the other in the air or on ice, you're stuck. Now the new rear factory "locker" from Chevy on the new Silverado, according to Chevy, is the ONLY factory locker available on the market in a pickup truck. With a true locker, you can basically take one of the rear wheels OFF of the vehicle and she'll still go. Quote Link to comment Share on other sites More sharing options...
BlackHorse Posted March 3, 2007 Author Share Posted March 3, 2007 Well, being that I've owned two Toyota vehicles I don't think I'm going to be labeled "anti" anything. I'm not excusing the drivers capabilities here either. But this was a little bump of snow in the road. Technically all the guy should need to do is very slowly back up and let the traction of the back tires pull him out of it. Heck if he had put it back in 2WD it probably would have done that. But then again, he's got this fancy computerized AWD computer system on his 4 Runner that is supposed to able to negotiate these simple things right? Quote Link to comment Share on other sites More sharing options...
StevenCaylor Posted March 3, 2007 Share Posted March 3, 2007 Question. On the new vehicles with AdvanceTrac, does the system handle situations like this, i.e., if one side of the vehicle is in the air or on ice, the brakes on that side (either front or rear) will be applied to transfer torque to the side with better traction? I have traction control on my Mustang and that's one of the features. Quote Link to comment Share on other sites More sharing options...
Hemiman Posted March 3, 2007 Share Posted March 3, 2007 The center diff is locked from the time it's put in 4wd. It's the "side to side" locking that wasn't happening and doesn't happen in all but the most serious off road equipment. So he was spinning one front wheel and one back wheel. Even in a "limited slip" rear axle, if you have one wheel on good traction and the other in the air or on ice, you're stuck. Now the new rear factory "locker" from Chevy on the new Silverado, according to Chevy, is the ONLY factory locker available on the market in a pickup truck. With a true locker, you can basically take one of the rear wheels OFF of the vehicle and she'll still go. Looked to me like only the pass front wheel was spinning some of the time. That's why I assumed the center diff wasn't locked. Again, I don't have much experience with the Toyota system. Quote Link to comment Share on other sites More sharing options...
ebritt Posted March 3, 2007 Share Posted March 3, 2007 Looks to me like you all saw what you wanted to see. But let's look at it with the anti Toyota glasses off. First of all, he has an open diff in front and in back. Many 4wd's come this way. The best you can do in most cases is a limited slip in the back and since both rear tires were sitting on ice, that wouldn't have done you any good. In only the most rugged off road set up do you have a locking front differential. Second, the video showed no less than four times he had it out of there and right when the vehicle was just getting ready to come out he hit the brakes, indicated by the brake lights and the tires not spinning. Third, he never did the "rocking" procedure that ALL of us Northerners know. So in a nutshell, there are two factors here: 1. Open diffs front and back, the same exact setup that 95% of all 4wd's run. 2. An incompetent driver. 1. I like my anti-Toyota glasses. They're stylish and comfortable. 2. I have been in that same situation with my Explorer and worse, it came right out...no problem. 3. An incompetent driver?? He was an incompetent customer....bought the wrong vehicle. Quote Link to comment Share on other sites More sharing options...
ebritt Posted March 3, 2007 Share Posted March 3, 2007 Question. On the new vehicles with AdvanceTrac, does the system handle situations like this, i.e., if one side of the vehicle is in the air or on ice, the brakes on that side (either front or rear) will be applied to transfer torque to the side with better traction? I have traction control on my Mustang and that's one of the features.In the air??Dude you need to slow down. Quote Link to comment Share on other sites More sharing options...
CPBroncoBoy Posted March 7, 2007 Share Posted March 7, 2007 Here's one I'm sure Ford doesn't want people to see. That doesnt prove anything... I have seen them all, and everyone has a different winner. All it was is the ford spun its tires and lost traction, once that happens the chevy can just pull them away. It's kind of like tractor pulling I guess, the idea is not to just hammer the gas but to get going slowly as to not loose traction. I dont trust any of those videos even if the ford wins cause they're all the same. Quote Link to comment Share on other sites More sharing options...
bec5150 Posted March 7, 2007 Share Posted March 7, 2007 That doesnt prove anything... Neither does the stupid Toyota video, but some folks here seem to think it does... Quote Link to comment Share on other sites More sharing options...
falconman13 Posted March 7, 2007 Share Posted March 7, 2007 In that video, the Ford doesn't look like it even turned a tire, The wheels are rolling backwards when the other truck pulls away. The smoke is from the other truck spinning its wheels, You would think if another truck was pulling you backwards, you would at the very least apply the brake Quote Link to comment Share on other sites More sharing options...
BlackHorse Posted March 8, 2007 Author Share Posted March 8, 2007 Neither does the stupid Toyota video, but some folks here seem to think it does... Woe, woe, calm down a little their bec5150. Nobody is saying that Toyota is all junk or something. Well except for maybe Richard, he really hates them. But it's not like Toyota doesn't make some good vehicles, because they certainly do. All some of us are saying is that the AWD system in this 4 Runner doesn't look to good in that video. Quote Link to comment Share on other sites More sharing options...
Paul Selby Posted March 8, 2007 Share Posted March 8, 2007 That doesnt prove anything... I have seen them all, and everyone has a different winner. All it was is the ford spun its tires and lost traction, once that happens the chevy can just pull them away. It's kind of like tractor pulling I guess, the idea is not to just hammer the gas but to get going slowly as to not loose traction. I dont trust any of those videos even if the ford wins cause they're all the same. And that was my point. Quote Link to comment Share on other sites More sharing options...
ford-boy Posted March 8, 2007 Share Posted March 8, 2007 (edited) QUOTE(CPBroncoBoy @ Mar 7 2007, 04:50 AM) That doesnt prove anything... bec5150 Neither does the stupid Toyota video, but some folks here seem to think it does... What it does show is that the Toyota did not have a limited slip 3rd member in the front OR back. Had this a "posi" rear, he would have been able to pull himself out. Contrary to what you posted earlier, the purpose of limited slip differentials IS to transmit power to both wheels via clutch packs or cones. If one rear wheel is on ice and the other is on pavement, the wheel on the ice will not be the only wheel turning. Power WILL go to the other wheel. This Toyota has what is called a "ONE LEGGER" in both axles, hence his problem. All "one leggers" or open differentials take the path of LEAST resistance and divert power to the wheel with no traction. Edited March 8, 2007 by ford-boy Quote Link to comment Share on other sites More sharing options...
bec5150 Posted March 8, 2007 Share Posted March 8, 2007 QUOTE(CPBroncoBoy @ Mar 7 2007, 04:50 AM) That doesnt prove anything... bec5150 Neither does the stupid Toyota video, but some folks here seem to think it does... What it does show is that the Toyota did not have a limited slip 3rd member in the front OR back. Had this a "posi" rear, he would have been able to pull himself out. Contrary to what you posted earlier, the purpose of limited slip differentials IS to transmit power to both wheels via clutch packs or cones. If one rear wheel is on ice and the other is on pavement, the wheel on the ice will not be the only wheel turning. Power WILL go to the other wheel. This Toyota has what is called a "ONE LEGGER" in both axles, hence his problem. All "one leggers" or open differentials take the path of LEAST resistance and divert power to the wheel with no traction. True, but that is the case with most 4wd's. You have to order limited slip to get it, and even a limited slip won't give you traction to both in the most extreme "one on ice, other on pavement" situation. For that, you need a full on locker and except for the new Silverado, you're SOL. I have had three 4wd's in my life and none had limited slip. They all did ok. Quote Link to comment Share on other sites More sharing options...
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