Clemsonfan15
New member
Damn dude. Calm down. Half of what I said was right. I'm just trying to learn a little.
1999 Awd??
- Thread starter ericdg16
- Start date
Jordan Petry
New member
I don't know if your questions been totally answered or not but I figured I would share my info on the topic... I love the 4wd unlocked feature, I use it all the time when in any sort of rain or snow. I have a real tough time going up steep hills in 2wd when the road is wet but all I gotta do is just hit the little button... Here's a picture...
Attachments
Jordan Petry
New member
hani1400 said:
I believe that it locks the center diff or T-Case whatever ya wanna call it... My dad has an 03 4x4 and we shut it off all the time because it shuts off the stupid VSC deal.
I'll summarize the systems the best way I can:
1996-1998 (All models):
Have 2HI, 4HI (with a press of the side button), 4LO (moving the lever). The button to 4HI can be pressed on the fly, but you must be stopped and in neutral to engage 4LO. No model had a center differential, therefore in 4HI and 4LO, the torque is split 50-50 front and rear and should not be used on dry pavement due to driveline binding.
1999-2000:
SR5 models have the same 4WD systems as 1996-1998 models.
Limiteds receive multi-mode 4WD with the inclusion of a locking center differential. Limiteds have 2HI, AWD with center differential open (with the press of the side button), real 4WD with center differential locked (moving the lever), the 4LO (moving the lever). The side button can be engaged on the fly, but you can only move the lever then stopped and in neutral.
The AWD mode is not really useful in my opinion. Since the center differential is open, if one tire loses traction, all the power will go to the spinning wheel only. For snow and offroad, true 4WD is best (center locked). I personally like the 4WD system on the 1996-1998 models because if I'm driving in conditions where I truly need 4WD, I like that I can just engage true 4WD at the press of a button instead of stopping, shifting into neutral, then moving the level to lock the center differential.
2001-2002:
All models receive the multi-mode system
2003-present:
Similar to the 3rd gen multi-mode system, but have a Torsen center differential that can be locked instead of the 3rd gen lockable open center differential. This is superior to the 1999-2000 system because the torque sensing center differential means that a loss of traction of one tire doesn't mean that all the power will be transfered and lost to that tire since front and rear axles will always receive some torque.
1996-1998 (All models):
Have 2HI, 4HI (with a press of the side button), 4LO (moving the lever). The button to 4HI can be pressed on the fly, but you must be stopped and in neutral to engage 4LO. No model had a center differential, therefore in 4HI and 4LO, the torque is split 50-50 front and rear and should not be used on dry pavement due to driveline binding.
1999-2000:
SR5 models have the same 4WD systems as 1996-1998 models.
Limiteds receive multi-mode 4WD with the inclusion of a locking center differential. Limiteds have 2HI, AWD with center differential open (with the press of the side button), real 4WD with center differential locked (moving the lever), the 4LO (moving the lever). The side button can be engaged on the fly, but you can only move the lever then stopped and in neutral.
The AWD mode is not really useful in my opinion. Since the center differential is open, if one tire loses traction, all the power will go to the spinning wheel only. For snow and offroad, true 4WD is best (center locked). I personally like the 4WD system on the 1996-1998 models because if I'm driving in conditions where I truly need 4WD, I like that I can just engage true 4WD at the press of a button instead of stopping, shifting into neutral, then moving the level to lock the center differential.
2001-2002:
All models receive the multi-mode system
2003-present:
Similar to the 3rd gen multi-mode system, but have a Torsen center differential that can be locked instead of the 3rd gen lockable open center differential. This is superior to the 1999-2000 system because the torque sensing center differential means that a loss of traction of one tire doesn't mean that all the power will be transfered and lost to that tire since front and rear axles will always receive some torque.
RonMAIDEN
Super Moderator
Hmmm,when i've driven my mom's '99 limited in the snow with the AWD engaged it's much betetr than my 4hi mode and it supposed to pull the power from the wheel that slips til it gets traction and that's the way it feels with my mom's truck.
Over the last 10 years she's owned it she rarely has used 4hi and only uses it when the snow has been more than 8" deep otherwise it's been the simple button push in the AWD mode.
I guess next time it snows real good I'll take her truck out and do a few tests since it has been a while since I've driven her truck in the snow.
Over the last 10 years she's owned it she rarely has used 4hi and only uses it when the snow has been more than 8" deep otherwise it's been the simple button push in the AWD mode.
I guess next time it snows real good I'll take her truck out and do a few tests since it has been a while since I've driven her truck in the snow.
maine runner
New member
Yesterday I experienced the limits of "AWD" in my '99 LTD.
While backing up a steep hill with a trailer in AWD, I hit a patch of ice (under 4" of snow), lost adhesion and one wheel spun. All momentum lost. After going back down the hill a few feet, shifted, drop the lever, shifted into R and zoom...right up the hill. No muss, no fuss.
While backing up a steep hill with a trailer in AWD, I hit a patch of ice (under 4" of snow), lost adhesion and one wheel spun. All momentum lost. After going back down the hill a few feet, shifted, drop the lever, shifted into R and zoom...right up the hill. No muss, no fuss.
RonMAIDEN said:
I'm pretty sure that 3rd gen 4Runners with the multi-mode system only had a simple open center differential that could be locked. In that case, the center differential doesn't have control over the torque distribution between the front and rear axles and therefore torque is not always sent to the right wheel. From a purely mechanical standpoint, true 4WD (50-50 torque split between front and rear) is always superior to AWD (open center differential) when it comes to getting maximum traction. The only problem is driveline binding when used on high traction surfaces. I can see AWD being good for a little extra traction on wet pavement though. I notice that my 4WD does bind in turns even on wet pavement.
RonMAIDEN
Super Moderator
JC_ez said:
AWD offers much more superior control on hard packed ice and snow and you see it with the rally cars. When any wheel loses grip the computer puts the power to only the wheels that grip and this is happening in milliseconds where when 4wd slips it's up to the driver to control wheelspin and it's only front to back.
I could swing the rear out in my Eclipse and keep the car slighty turned sideways but still going straight and do this on purpose with just throttle inputs.
I used to ice race my AWD Eclipse on a couple of frozen lakes and I can tell you AWD is much better than just the simple 4wd system in most of our 4Runners. Maximum traction to get going (or getting unstuck) might be better with 4hi but control is better with the AWD system once you are moving especially at higher speeds.
KellyJ
New member
RonMAIDEN said:
So basically when I push in the 4WD button on my Limited, I'm really switching from 2WD to AWD? There should be some better clarification from Toyota on this issue (like a sticker/ card in the interior stating it ["it" being the fact that you only get true 4WD when you lock the center differential])
But I guess Toyota figured that this information wouldn't really matter one way or another to the majority of people who do purchased their 4Runners. Which is confusing, given the capabilities of all 4Runners
RonMAIDEN said:
I agree with you on your AWD arguments. The only reason I think 4WD is better (or more useful) on 3rd gen 4Runners vs. AWD is because the 3rd gen 4Runner doesn't have a computer that automatically controls and torque distribution of the differentials. The center differential is either manually locked, or unlocked and fully open. Therefore in the case of the 3rd gen 4Runner with multi-mode in AWD mode, it only takes one wheel that loses traction to leave all other wheels with no torque. In 2001-2002 Toyota introduced ATRAC to the 4Runner which kind of makes up for this, but it uses the braking system, not the drivetrain. The 4th gen 4Runner fixes some of these issues by using a Torsen center differential that can also be manually locked.
KellyJ said:
I see you drive a 2002 Limited. From my experiences driving my friends 2002 4Runner, when you press the button, you go from 2HI to AWD (power to all 4 wheels, center unlocked). You should have a button on your dash beside the dashlight dimmer that is the center differential lock. When you press this you go from AWD to 4HI (center locked). There is no rear locking differential on 2001-2002 models, but instead, Toyota offered ATRAC.
KellyJ
New member
JC_ez said:
Yeah, that is what I figured. The button on the side of my transfer case lever should say AWD then, and not 4WD is what I'm saying. IMO, ATRAC really hampers my 2002's capabilities offroad. For on road applications, it seems to work relatively well.
Remedying the traction issue with 01-02's can be done by either pulling the main ABS (green) fuse in the engine bay or doing the Andymod, but with either comes the loss of ABS which makes me a little uncomfortable
Hi, just signed up but I've been using the site for a while and appreciate all the good info here. I hope i'm not hi-jacking the thread but it relates. I recently put my '00 (SR5, 4wd, auto) in a snowy ditch, 2 wheels in the ditch and 2 on the road and ended up stuck. I have the j shifter with 2hi, 4hi and 4lo. Once stuck I put it in 4lo. When I was able to get traction under 3 wheels (jamming logs and sticks), the 4th slipped and I stayed stuck. I switched the wheel that didn't get the traction - front, back, l, r - and same each time. So no matter what, everytime a wheel lost traction, that one would spin. If it was just a rear wheel spinning, wouldn't the front 2 be engaged to push it out? Why does one wheel spinning cut the torque to all other wheels while I'm 4lo? Does this sound right?
Big Gas said:
Your 4WD system is similar to the one on my 1997 Limited. Our trucks do not have a center differential and therefore splits the torque 50/50 with the front and rear axles.
The problem is that the front and rear differentials are open. That means that when we are in 4HI or 4LO, even though there is a 50/50 torque split between the front and rear axles, you will get stuck if one front AND one rear wheel loses traction.
If you have a rear differential locker, then with the locker engaged, even if one of the front wheels were to lose traction, the 2 rear wheels would still get 50% of the torque. If only ONE of those rear wheels had traction, you wouldn't get stuck.
Something is not right. If you have 3 out of your 4 wheels have traction in a standard 4wd system you should be able to drive right through it.
Hard to diagnose just reading your post, but if you really tried switching which tires had traction my best guess would be a busted front hub.
If one of your front hubs is busted you will know cause neither one of your front tires will ever get power. The front diff just sends all the power to the busted hub which free spins and keeps the other side from getting power.
This happened to me in an old nissan I used to have and I found out while driving through a ravine. However you mentioned that if you gave both back tires traction then if one of the front ones spins you still wouldn't get out (somethings not right with that)
