| duffjen |
I took delivery today on my wife's new 05' Pilot. The salesperson told me the VTM 4 Lock, locks the pairs of front and rear tires so they turn the same speed (left and right sides) as you drive, kind of like a Detroit Locker.
I thought the VTM 4 Lock locked the front and rear into a 50/50 split of the power, but did not affect the side to side traction?
Please excuse my lack of knowledge of the proper terms.
ps, I love this thing, I am so jealous of my wife!! I get her 00' Maxima .
Thank you
Kevin
Atlantic City NJ |
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| HenryBravo |
I'm going to paraphrase from the owner's manual:
Under normal conditions, the Pilot is essentially a front-wheel drive vehicle. Under lower traction conditions, the Variable Torque Management system automatically transfers varying amounts of engine torque to the rear wheels. When you engage the VTM-4 Lock system, it applies a steady non-varying amount of torque to the rear wheels. Even in VTM-4 Lock mode, the rear tires are not suppose to spin according to the owner's manual.
HB |
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| tlaudio |
If I remember correctly....
You must be in 1st or 2nd gear OR Reverse.
Once you exceed 18mph the 4-wheel lock system will turn off.
It is used to get the Pilot Un-stuck....or tow a boat out of the water....etc...
TL |
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| N_Jay |
quote:
Originally posted by duffjen
I took delivery today on my wife's new 05' Pilot. The salesperson told me the VTM 4 Lock, locks the pairs of front and rear tires so they turn the same speed (left and right sides) as you drive, kind of like a Detroit Locker.
I thought the VTM 4 Lock locked the front and rear into a 50/50 split of the power, but did not affect the side to side traction?
The VTM-4 Lock locks both rear wheels to the driveline, which is the average speed of the front wheels.
One front wheel can still spin, but in doing so both rears will have to speed up and the added "push" usually limits the front wheel spin.
Ther is no true rear differential. There is not center differential.
Concepts like 50/50 torque split and 50/50 power split are not good explanations for how power is distributed in a 4WD system (put without assuming everyone is an engineer, there are not any that are much better). |
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| robrecht |
quote:
Originally posted by N_Jay
The VTM-4 Lock locks both rear wheels to the driveline, which is the average speed of the front wheels.
One front wheel can still spin, but in doing so both rears will have to speed up and the added "push" usually limits the front wheel spin.
Ther is no true rear differential. There is not center differential.
Concepts like 50/50 torque split and 50/50 power split are not good explanations for how power is distributed in a 4WD system (put without assuming everyone is an engineer, there are not any that are much better).
N_Jay, that's the clearest, simplest explanation yet. Thanks! |
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| duffjen |
Thank you very much, I am overwhelmed by all the new gadgets. I guess I should have read the owners manuel more closely, but you know what they say "That's the manufacturers opinion on how it should be done!"
I am just kidding, I would never deviate from their instructions!
Kevin
Atlantic City NJ |
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| FamilyGuy |
quote:
Originally posted by duffjen
The salesperson told me the VTM 4 Lock, locks the pairs of front and rear tires so they turn the same speed (left and right sides) as you drive, kind of like a Detroit Locker.
The proper name for this would be a "limited slip rear differential," (my slang for it is posi-trac) and can be had on many 2wd vehicles, as well as 4wd vehicles. Mostly on RWD or full size trucks.
Makes me wonder if the salesperson came from Ford or Dodge background. More likely he has been selling Hondas for many years and is very successful at it. It seems like many of the best salespeople really no very little bout the true mechanics of the products..... |
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| N_Jay |
quote:
Originally posted by FamilyGuy
The proper name for this would be a "limited slip rear differential," (my slang for it is posi-trac) and can be had on many 2wd vehicles, as well as 4wd vehicles. Mostly on RWD or full size trucks.
Makes me wonder if the salesperson came from Ford or Dodge background. More likely he has been selling Hondas for many years and is very successful at it. It seems like many of the best salespeople really no very little bout the true mechanics of the products.....
Actually in a way it is closer to a locking differential, than a limited slip.
Remember there is NO differential.
Just a ring gear and some clutch plates. |
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| duffjen |
Family Guy,
I was very happy with my dealer and salesperson, I read a lot about this car and the 4Runner before I decided to purchase this one.
I suspected what he was telling me was somewhat the best way he could explain the 4 wheel drive system but the way he described it made it sound similar to the differentials on the old miliatry trucks. Only special vehicles have those serious locking rears and I understand that.
Otherwise I was extremely happy with my salesperson and the dealer all together. I will make certain their business is added to the appropriate section.
Kevin Devlin |
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| tangotango99 |
| hey N Jay,I believe Honda ask for u r input to build the pilot VTM 4 Lock :2: |
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| timchen |
limited slip differential left to right. clutched differential drive shaft to rear axle.
That means it can clutch lock rear axle to drive shaft. lock the average speed of two rear wheels to average speed of front wheels. Note since it's clutch lock, it can still slip under brute force.
left and right are limited slip diff, which says it allow some speed difference before lock....
Well, it just give you piece of mind you have a AWD. very good for slippery surface while consider fuel eco but not for real off road. |
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| N_Jay |
quote:
Originally posted by timchen
limited slip differential left to right. clutched differential drive shaft to rear axle.
That means it can clutch lock rear axle to drive shaft. lock the average speed of two rear wheels to average speed of front wheels. Note since it's clutch lock, it can still slip under brute force.
left and right are limited slip diff, which says it allow some speed difference before lock....
Well, it just give you piece of mind you have a AWD. very good for slippery surface while consider fuel eco but not for real off road.
There is NO differential in the rear.
The clutches lock the side to the ring gear. Unlike a differential neither wheel can be driven faster than the ring gear, no matter what the other side is doing.
The only affect one side would have on the other is teh slowing of the driveline due to load. (typically load in low when the wheel is slipping.
Yes the clutches can slip under high load. I am sure they do, but doubt the opperate in slip mode much due to the short service life they would have.
As for the front, it is a simple open differential. if one when spins faster, the other HAS to spin slower. Its all gears there is no room for "slip" except at the tires.
As for the "real off road" quote, I don't think there is a text book definition. I would bet there are situations where the VTM-4 system outperforms traditional 4WD, and situations where it is worse.
I would be more concerned about the lack of low range, the soft suspension, and lack of under-body protection more than the capabilities of the 4WD system. |
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| sski |
Real world example...correct me if I'm wrong.
Winter...you slide the Pilot into a ditch. Right side in the ditch, left side on the shoulder. In VTM4-lock, there should be power to that rear right wheel to help push you out.
I had the exact situation with my CR-V. With CR-V the left wheels spun helplessly while the right wheels just sat there. With the help of some manpower the CR-V got out. |
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| N_Jay |
quote:
Originally posted by sski
Real world example...correct me if I'm wrong.
Winter...you slide the Pilot into a ditch. Right side in the ditch, left side on the shoulder. In VTM4-lock, there should be power to that rear right wheel to help push you out.
I had the exact situation with my CR-V. With CR-V the left wheels spun helplessly while the right wheels just sat there. With the help of some manpower the CR-V got out.
With the VTM-4 locked there will be power to BOTH rear wheels. As long as one or the other (or a combiation) has enought traction to move the vehicle forward against whatever is holding it back you will be able to get out. (assuming you have enought power to move.)
The CR-V has open differentials, therefor if one wheel on both the frong and back can slip, the other wheen can only get power up to the point the slipping ocures. Thi sis teh same as most traditional 4WD systems. |
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| sski |
Sorry, I meant both wheels would get power but the right is the one that going to get you out because it has all the weight over it.
I have two neighours with Ford Explorers (03 & 04) that use my boat ramp (dirt/gravel). In both cases I always heard some momentary wheel spin as they pull up the ramp. I have never had the Pilot spin (and thats without VTM4 locked). The only time I've ever needed the Lock is climbing the driveway in about 1 ft of snow. |
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| N_Jay |
quote:
Originally posted by sski
Sorry, I meant both wheels would get power but the right is the one that going to get you out because it has all the weight over it.
I have two neighours with Ford Explorers (03 & 04) that use my boat ramp (dirt/gravel). In both cases I always heard some momentary wheel spin as they pull up the ramp. I have never had the Pilot spin (and thats without VTM4 locked). The only time I've ever needed the Lock is climbing the driveway in about 1 ft of snow.
Hopfully!
Weight is only one part.
Traction and leverage are also important. |
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| sski |
| Agreed. My point really is that, all else being equal, the Pilot stands a better chance of climbing out than the CR-V. |
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