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tinol2000
Date registered: Dec 1899
Location:
Vehicle(s):
| Question about 4x4 on W463
Hi,
I am trying to get an understanding of how the 4x4 works on the W463. First when nothing is applied what where is the traction. Second When the central lock is applied what happens to the traction as opposed to when nothing is applied. Third and fourth what happens when rear and front lockers are applied. The most confusing part for me is the central lock function and how it relates to the 4x4 system.
Thank you |
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KERR
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Question about 4x4 on W463
1) full time awd.... so its always in 4wheel dirve.
2) center lock locks the front and rear drive shafts together in the trasfercase... splits power 50 / 50 to the front axle and rear axle..
3) real locker lockes both passanger and driver side tires together... both tires spinn the same amount
4) same as above,
5) in the end all the drive train is locked together. So if you had 3 wheels off the ground the car would still move as long as the one tire had the traction to move it...
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tinol2000
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Question about 4x4 on W463
First let me say tahk youfor the reply and I have 2 more questions. When in AWD does the traction rotates to the tire with the least traction? Another question. Is is true that when in AWD there is a separate gear motor unit that drive the truck as opposed to the T/C itself.
Thank you |
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4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| Re: Question about 4x4 on W463
its all on my site.
http://4x4abc.com/4WD101/abc3.html
http://4x4abc.com/4WD101/abc4.html
http://4x4abc.com/4WD101/abc5.html
Looking at a vehicle with full time 4WD and a lockable center diff. The torque distribution on equal traction surface front/rear is 50/50 without the center diff lock engaged. But when traction becomes unequal (slippery stuff or weight shifts) one wheel on one axle (lets say the right rear) could start slipping and spinning and trigger the rear drive shaft to rotate faster than the front driveshaft. No, no power is lost and torque split is still 50/50 on both the center diff and rear axle diff - only the amount of torque created is determined by the wheel/axle with the least traction (the amount of torque is always double the amount possible at the wheel/axle with less traction - and this total amount might net be enough to move the car).
To prevent the rear drive shaft to rotate faster, prevent the vehicle from becoming immobile, the center diff lock is engaged (you do this before you get stuck!). By doing so the torque split will be determined by how much resistance (traction) each axle has. Front axle with more traction will create more torque than the rear axle with less traction. Both amounts combined (now higher than with the center diff disengaged) will be able to move the car.
Using the axle diff lock at the same time will make it possible to create even more torque. More torque because the total torque amount per axle is no longer determined by the wheel with less traction but rather by the traction of both wheels.
So, against common misconception:
open diff = torque distribution is always equal (even with spinning wheels), highest with equal traction, but the amount might not be enough when traction is unequal
locked diff = torque distribution is only equal when traction is absolutely equal (same amount as open diff with equal traction), with unequal traction the torque distribution (split) is unequal but combined amount is as high as with equal traction. So, 50/50 torque split with locked center diff is BS.
Important result: in open diffs the components left and right of the diff (axle shafts or drive shafts) never have to handle more than 50% of the torque going into the diff - however, in locked diffs one side can experience 100% of the torque going into the diff. That makes it necessary to have much stronger components. That in turn makes vehicles with 3 diff locks heavier and much more expensive. Can you say "G:? |
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JamesG
Regular
Date registered: May 2006
Location: Conifer, Colorado
Vehicle(s): 2011 G550, 2000 L.C.,1997 L.C.1987 FJ60
Posts: 98
| RE: Question about 4x4 on W463
Harald, The reference to stronger components begs the question; does installing an ARB air locker compromise drivetrain components in a vehicle that wasn't built around them? ARB offers a wide variety of applications as you know. Where would the weak link be after an install? For example, an 80 series Landcruiser W/O factory lockers. Also doesn't the Rubicon Jeeps have larger Dana axles with factory lockers?
Sorry if I jumped the thread. Thanks Harald. |
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the user name
Date registered: Dec 1899
Location:
Vehicle(s):
| Re: Question about 4x4 on W463
does applying 4x4 in g class is the same case for automatic tranny or manual tranny? |
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AlanMcR
Expert
Date registered: Apr 2006
Location: US, CA, Los Altos
Vehicle(s): G300DT E300DT 230SL
Posts: 3500
| Re: Question about 4x4 on W463
the user name - 5/24/2007 9:23 PM
does applying 4x4 in g class is the same case for automatic tranny or manual tranny?
Yes, the transfer case is physically separated from the transmission by a short drive shaft. It really doesn't care what is generating the input torque. The transfer case should only be shifted (High/Low) with no torque, so the transmission needs to be in neutral, or the clutch pressed. |
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4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| RE: Question about 4x4 on W463
Keith,
you are right, installing a locker of any kind into an axle that was not designed to handle the higher torque load is asking for trouble. Unless you have a Toyota. All straight axle shafts are strong enough to deal with lockers. In order to have as many identical parts as possible (cheper) Toyota installed equally strong shafts in all axles - locker or not. However, the Toyota IFS axles shafts are NOT strong enough for lockers (that's why Toyota does not offer any.
The Jeep Rubicon is a mixed bag of good and bad. The advertising is not as informative as a serious user would want it.
Only the axle housing is Dana 44 - the diff and locker are from Tochigi Fugi (better than a 44), but shafts and joints are not Dana 44 (and known to break). Also, Jeep publishes that the diffs are 4.11:1 but the teeth are 45 ring to 11 pinion = 4.09:1 - but who cares about truthful details when you can sell a lot of cars. |
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ez rhino
Date registered: Aug 2006
Location: Charlotte, NC
Vehicle(s): 2010 Rubicon Unlimited; 2009 Mini Clubman JCW
| Re: Question about 4x4 on W463
Interesting Harald. So if somebody has, say a 2002+ full size Montero/Pajero with IFS/IRS, would you say ARB's are a bad idea? I always thought a slightly lifted Montero with lockers would be a good all around vehicle if I ever had to sell the G, but now you've got me thinking 90's Land Cruiser. |
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4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| Re: Question about 4x4 on W463
Matt,
the 90's Landcruiser has lockers front and rear. Quality at least as good as G. Strong performer. Poor mpg.
As long as ARB makes a locker you stick it in. Most IFS have not so strong axle shafts (2 CV joints on each) - including the H1. However, I believe that even axles not designed to take lockers are strong enough to handle the extra torque (I have had a CJ7 for my clients for 15 years with no axle upgrades but 2 ARB - and never broke anything during the most demanding driving), after all, the engineers always build a little safety into the parts.
Key is how you as the driver use your equipment. Since most don't know how to use 4x4, let alone lockers, they simply grenade everything they own (forums and youtube are full of those "It broke on me" stories - and it should be: "Mom, look, I broke it"). Most drivers believe power will get them through or over - but its brains and finesse that make you succeed (without ever breaking anything). |
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JamesG
Regular
Date registered: May 2006
Location: Conifer, Colorado
Vehicle(s): 2011 G550, 2000 L.C.,1997 L.C.1987 FJ60
Posts: 98
| RE: Question about 4x4 on W463
Thanks Harald for the info. As you say, finesse your way in and out of the wilderness, less walking  This reminds me of an incident on Red Cone Pass some years ago. About an hour into the trip a Jeep comes up behind me, right on my bumper and actually layed on his horn! I moved over and let him by without incident. (could be armed) and with daughter. Caught up with him later, off to the side changing a flat  |
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4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| RE: Question about 4x4 on W463
Keith,
I have had guns pointed at me to underline their wish to pass (faster than I was moving out of the way) and I have had tires sliced for letting someone pass (it was simply too narrow for more than one).
Wise Chinese and Japanese knew for a long time - there is incredible (inner) power through calmness. Hurry up and fail!
http://www.brainfuel.tv/ |
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79percent
Extreme Veteran
Date registered: Apr 2006
Location: Remscheid / Germany
Vehicle(s): 300 GE
Posts: 537
| RE: Question about 4x4 on W463
look here for better understanding... http://www3.mercedes-benz.com/e/cars/g-class/special04/content/gelaende_differential.swf |
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4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| RE: Question about 4x4 on W463
description is completely wrong! This is gaga talk for newborns. Power does not move the car. |
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79percent
Extreme Veteran
Date registered: Apr 2006
Location: Remscheid / Germany
Vehicle(s): 300 GE
Posts: 537
| RE: Question about 4x4 on W463
maybe I miss here something, what's wrong with it?
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BusBar
Extreme Veteran
Date registered: Apr 2006
Location: UK. North West / Wales
Vehicle(s): 463 300GDL, 460 280GEL
Posts: 382
| RE: Question about 4x4 on W463
One of the most amusing episodes I’ve watched is a guy in a Discovery (same 4WD system as a 463) doing his best to bury it on a beach. Absolutely revving the proverbial out of it without the centre diff locked I.E in one wheel drive.
A women walking along the beach stopped and was obviously trying to explain where he was going wrong, she eventually lent through the side window and engaged the centre diff lock for him. At which point the Disco (without much input from the dimwhit behind the wheel) extracted itself and off they went……………..priceless  |
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4x4abc
Date registered: Apr 2006
Location: La Paz, Baja California, Mexico
Vehicle(s): 02 G500
| RE: Question about 4x4 on W463
RH,
there is no "one wheel drive" in a 4x4 - ever!
No "two wheel drive" either, unless selected.
Its always 4 wheels moving the car. Diff locks or not.
However, it depends on the driver how he manages the torque distribution.
No lockers (not even the center) engaged = torque is equal on each wheel, but total amount of torque often not enough to keep the car moving.
With lockers engaged = torque distribution is not equal on each wheel, but since the wheels with traction (the counter force for torque) can develop a lot of torque, the car can keep moving.
Downside of engaging lockers is (we addressed this earlier in the thread) that the shafts leading to the wheels with traction will be exposed to a lot of torque and can break if the driver is heavy on the gas.
There is a lot of gaga talk on 4x4 forums about "drive wheels" and such. As I said - complete gaga.
Even some of the US 4x4 experts teach "...that 4WD is not really 4WD. It is only 2WD." (Bill Burke on his web site). Yikes!
A lot of engineer's knowledge went into the creation of 4WD and the various traction management systems. Especially in a G. The potential for great performance is there. But without the capability of the driver to (manually - and that's the challenge) operate a complex traction control system, the well engineered piece of machinery will either go nowhere or break up in parts. |
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BusBar
Extreme Veteran
Date registered: Apr 2006
Location: UK. North West / Wales
Vehicle(s): 463 300GDL, 460 280GEL
Posts: 382
| RE: Question about 4x4 on W463
Harald excuse my artistic licence on this one, I know you are correct in your statements I was just emphasising peoples complete lack of understanding re. 4WD. I have witnessed people looking at their “4WD” in complete bewilderment when they have managed to get stuck with one wheel having virtually zero traction. E.G dangling in mid air
Indeed I have demonstated this by placing one wheel of a Defender on to rollers and asking the driver to attempt driving it away. It’s amazing how many fail to figure out what’s going on even when they have used these types of vehicles for years.
Russ
Edited by BusBar 5/26/2007 7:26 AM
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BusBar
Extreme Veteran
Date registered: Apr 2006
Location: UK. North West / Wales
Vehicle(s): 463 300GDL, 460 280GEL
Posts: 382
| RE: Question about 4x4 on W463
BTW absolutely no offence intended to the original questioner with respect to my previous posts, you have done exactly the right thing. Ask questions and obtain an understanding before you jump in at the deep end or worse still proceed with blind arrogance
Edited by BusBar 5/26/2007 12:08 PM
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