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handsomeDave
Guest
What's the difference between stock AWD and 4x4? Does 4x4 have a locked front/rear differential, and AWD is open?
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NitroTy
Guest
AWD typically has either an viscous center differential, or a variable clutch for controlling the power to the front or back axle. AWD is also often automatic (in the case of a variable clutch), whereas 4x4 has a locked "center differential" (part of the transfer case), giving full power to both front and back axles when engaged.
4x4 tends to be built sturdier and used on rear wheel drive vehicles, while AWD is used mainly on front wheel drive vehicles.
4x4 tends to be built sturdier and used on rear wheel drive vehicles, while AWD is used mainly on front wheel drive vehicles.
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handsomeDave
Guest
alright, thanks, for clearing that up
:beer:
:beer:
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Root Moose
Guest
Some of the old square Subie wagons from the 1980s had low range. IIRC the Oz spec Foresters still get a low range box - well, maybe not the new, new Foresters. The late 90s ones did for sure.
Also, full-time is AWD as far as I am concerned. So, basically any modern Land Cruiser, G-Wagen or Land Rover could be considered a AWD vehicle. Any of the old 1970s domestics that used the NP203 could be considered AWD as well. These all have a low range in them.
There's a lot of marketing babble out there about AWD and stuff. In a nut shell, if the vehicle has a center differential that allows variation of speed between the front and rear axle then it is AWD.
NV242 in it's various incarnations is a great case. You can mix and match parts between the Jeep and HMMVW version to make an ?ber case with 2wd, FT/AWD, PT, 4LO while having 32 spline outputs. There's no official torque rating for it but it has to be at least the same as the HMMVW version in AWD mode. It would be stronger than a built NV231 but not as a strong as a NV241OR.
Also, full-time is AWD as far as I am concerned. So, basically any modern Land Cruiser, G-Wagen or Land Rover could be considered a AWD vehicle. Any of the old 1970s domestics that used the NP203 could be considered AWD as well. These all have a low range in them.
There's a lot of marketing babble out there about AWD and stuff. In a nut shell, if the vehicle has a center differential that allows variation of speed between the front and rear axle then it is AWD.
NV242 in it's various incarnations is a great case. You can mix and match parts between the Jeep and HMMVW version to make an ?ber case with 2wd, FT/AWD, PT, 4LO while having 32 spline outputs. There's no official torque rating for it but it has to be at least the same as the HMMVW version in AWD mode. It would be stronger than a built NV231 but not as a strong as a NV241OR.
Farm Boy
Bought the Farm
Exactly the point.
The NP203 is not an AWD case as the front and rear outputs will always spin the same speed (unless something is broken) making it full-time
Chris, I'm suprised. I would have figured you to be the first one to disagree with this statement, not to make it.
You must be getting into the Christmas sauce a bit early and loosing your attention to detail. :flipoff:
Mitko, does your tcase have some sort of center diff that allows for the variation in front/rear output speeds?
Or is it more of RWD and the front engages when sensors detect wheel slippage?
:beer:
NP242's "full-time" setting is for use on pavement and does slip front to back as there is almost non-existent binding when turning on dry pavement whereas when you are in "part-time" mode it is definitely locked front and rear, I ran a 242 until I put in the D300 and 231 doubler. Interesting fact though is that I once blew a rear tire 2km from home and just decided it was easier to roll it backwards on the dolly and tow it. In park but in 2wd when I pulled away the front wheels were locked solid, I was crossing an exit to a blind corner and was pawing the shoulder to get going so I thought it was just a soft shoulder but looking in my mirror I saw the wheels locked but kept on the coal until I dragged it to the other shoulder, (the turbo was spooled up pretty good on the Excursion) then I had to put the tcase in neutral because even slipping the transmission into neutral did not work. The transfer case was pretty bound up at that point. Also the newew Cherokee's with V8's have a NP249??? that does have a low range but slips automatically until it sees difference in wheel speed and then locks the front and rear together. (which makes a pretty ugly noise if you happen to have the rear wheels spinning like crazy)
Mine is a AWD. Center diff with selectable locker and low range. Option of having the low range in AWD mode (center diff not locked) and at full time 4WD (center diff locked), whereas the Jeep NV 242 TC has the low range only at Full time 4wd.
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Root Moose
Guest
I think we may be having a disconnect due to diction or something.
If the shafts are locked front to rear then it is a part-time case (part-time as in not meant to be run on hard surfaces)
Here's a diagram of a NP203; see item number 18. That is the differential that allows different speeds between the front and rear shafts (i.e. AWD).
http://www.offroaders.com/tech/Diagrams/np203.htm
More discussion:
http://www.off-road.com/trucks4x4/article/articleDetail.jsp?id=199953
http://www.4wheeloffroad.com/howto/47538/index.html
Were you thinking NP205 maybe?
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Root Moose
Guest
At the expense of being even more pedantic, the NV242 only has low range in part-time mode (i.e. locked center differential).
It's an honest mistake though - the way the NV242 is shifted you pass through PT mode to get to FT mode from 2wd mode so you could assume that Low is also in FT mode. But it is indeed in PT mode when in 4Low (i.e. center differential locked).
Additional useless trivia: the torque split on a NV242 is 48%/52% for front/rear.
C'mon, I had to at this point.
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Farm Boy
Bought the Farm
Additional useless trivia: the torque split on a NV242 is 48%/52% for front/rear.
C'mon, I had to at this point.
Now that's more like you
I stand corrected on the 203. I've even got one of them in parts and don't remeber seeing that.
Is there something else that I'm missing that provides some sort of lock/limiting to this (new to me) center diff? The diagram looks like a open diff which if I'm right, combined with open axle diffs, you could theoretically still have one-wheel drive, even though it's suposed be 4x4
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Root Moose
Guest
No worries. I've only ever tripped over a NP203 in the wrecking yard so I'm not 100% on this: my understanding is that there is a position on the shifter that locks the differential when you move from FT to PT. I don't know how the internal mechanism works.
The other thing is that it was fairly common to convert them to a PT only case.
Mitko, the Gwagen case is divorce mounted. Has there been issues with the mounts getting ripped up or whatever when the truck is really used for wheeling? I've never heard of anything like that but then I don't follow the Gwagen stuff that closely.
The other thing is that it was fairly common to convert them to a PT only case.
Mitko, the Gwagen case is divorce mounted. Has there been issues with the mounts getting ripped up or whatever when the truck is really used for wheeling? I've never heard of anything like that but then I don't follow the Gwagen stuff that closely.
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kbrousseau
Guest
I never had problem with the TC mounts on both my trucks although I am not wheelin the new one. But the old one was put under a lot of abuse and never had problems. I've heard from other owners that someimes someone have them worned out but not really often. Pretty stout bushings though.
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ajh
Guest
I used to have a Mazda 323 GTX. it was a full time AWD but had a little button in the center console to lock up the center diff for a true 4wd. no low range tho
So it also had locking hubs?