1st drive in snow with '01 Limited

[thenightman]

It seems like toyota using the words "diff lock" regarding the tcase causes a lot confusion for some people. I bet if you asked some which is more capable off road, a 2001 with a diff lock, or a 97 with a diff lock, they would consider them equally capable, because they both "have lockers". It would have been much clearer if they had only referred to these things as having a AWD mode and a 4x4 mode.

 

[gamefreakgc]

I've spent a decent amount of time in snow, I don't live it in but I play in it. Tires mean more than locked/unlocked or 2WD/4WD. I used to have some A/T tires and they were good in the snow, very confident going and stopping. Terrible in the rain! I changed the tires to H/T and they are awesome in the rain but absolutely terrible in the snow! That might be why some people say "lockers suck".

I have an LSD in the rear, for reference.

 

[Cree]

I join in on that question also. I totally understood my 2000 with the jcase and rear locker, drove that for 5 years in heavy snow and ice.
Now my 2001 im still not sure when to lock the center diff. Im driving in snow and ice all the time ( Novemeber to April) and guess im just in AWD ? Guess I use it when IM slipping, but havent had that issue yet as I drive smart.

When you are in 4WD, with all shafts spinning the same speed, both axles spin at the same rate, so if one breaks traction there's no torque split, no slipping anywhere that allows the other axle to compensate.

In AWD (Transfer Case OPEN), the axles and spin at different speeds, so say if you give it too much throttle and lose the rear, the front may keep traction and keep pulling you out of the mess you're in, whereas in 4WD once you start gaining wheel speed it'll just keep going and break traction.

It seems like toyota using the words "diff lock" regarding the tcase causes a lot confusion for some people. I bet if you asked some which is more capable off road, a 2001 with a diff lock, or a 97 with a diff lock, they would consider them equally capable, because they both "have lockers". It would have been much clearer if they had only referred to these things as having a AWD mode and a 4x4 mode.

Toyota calls it a multi-mode transfer case, not a locking center differential. The confusion is generated by owners hoping that they have something special and dealers advertising it as some kind of feature.

To be clear if I wasn't already, my gripe is that a lot of multi-mode owners, especially 01-02 guys for some reason, act like it's some rare thing or list it when they talk about their their trucks (I have an 02 with Center Locking Diff). All of the 4WD trucks in 01-02 came with it. It's literally part of the design. You couldn't buy one without it. They didn't make any with out it. It's literally the exact same transfer case as what came on the 99-00 Limited, they just moved a couple of buttons (and probably changed the 4WD comp and harness if we're being fair). The shift actuator, to my knowledge, is the only thing that changes between the two year ranges mechanically.

This isn't aimed at anyone, it just annoys me.

 

[dmppdx]

When you are in 4WD, with all shafts spinning the same speed, both axles spin at the same rate, so if one breaks traction there's no torque split, no slipping anywhere that allows the other axle to compensate.

In AWD (Transfer Case OPEN), the axles and spin at different speeds, so say if you give it too much throttle and lose the rear, the front may keep traction and keep pulling you out of the mess you're in, whereas in 4WD once you start gaining wheel speed it'll just keep going and break traction.

Maybe I'm just misinterpreting what you are saying, but isn't it the opposite? For more advanced cars where the center differential is basically a limited slip, it limits the amount of slippage, and in really advanced cars with variable slip that's controlled by the car's computer, it works to shift power to what ever set of wheels that has traction. The the 4runner has an old fashioned center differential that basically an open differential in AWD so if both back tires start to slip, all the power is going to go to the rear and none to the front. With the center differential in 4wd, the front and back need to spin at the same rate, so even if both back lose traction, as long as the fronts have traction, you will still move since power is going to them. I think in normal snow driving, its best to drive in AWD since when going around corners, the open center differential allows the front and rear to move at different speeds, which is good since they go through turns at different radius and it allows the tires to not need to break traction. In 4wd, when going around corners, one of 4 tires is going to have to loose traction by either going faster or slower than the surface it is on since front and back sets of tires need to go at different speeds and one tire is going to have to compensate for that difference. That means you will have only 3/4 the traction as normal. That is also why you don't want to drive in 4wd on dry pavement since you basically will be dragging one tire on every corner.

I have a bmw m3 with a limited slip rear differential and in the snow, with snow tires its crazy good climbing snow covered hills if I'm going in a straight line, but once you go around any slight corner, the limited slip differential turns into a locked rear differential since the traction from the snow isn't enough to allow the tires to move at different rates so it basically drags one tire and you end up just with one tire with traction and it really struggles and the back end has a tendency to slides around. Not exactly the same, but similar concept

 

[Cree]

Maybe I'm just misinterpreting what you are saying, but isn't it the opposite? For more advanced cars where the center differential is basically a limited slip, it limits the amount of slippage, and in really advanced cars with variable slip that's controlled by the car's computer, it works to shift power to what ever set of wheels that has traction. The the 4runner has an old fashioned center differential that basically an open differential in AWD so if both back tires start to slip, all the power is going to go to the rear and none to the front. With the center differential in 4wd, the front and back need to spin at the same rate, so even if both back lose traction, as long as the fronts have traction, you will still move since power is going to them. I think in normal snow driving, its best to drive in AWD since when going around corners, the open center differential allows the front and rear to move at different speeds, which is good since they go through turns at different radius and it allows the tires to not need to break traction. In 4wd, when going around corners, one of 4 tires is going to have to loose traction by either going faster or slower than the surface it is on since front and back sets of tires need to go at different speeds and one tire is going to have to compensate for that difference. That means you will have only 3/4 the traction as normal. That is also why you don't want to drive in 4wd on dry pavement since you basically will be dragging one tire on every corner.

I have a bmw m3 with a limited slip rear differential and in the snow, with snow tires its crazy good climbing snow covered hills if I'm going in a straight line, but once you go around any slight corner, the limited slip differential turns into a locked rear differential since the traction from the snow isn't enough to allow the tires to move at different rates so it basically drags one tire and you end up just with one tire with traction and it really struggles and the back end has a tendency to slides around. Not exactly the same, but similar concept

You're right. What I get for replying with a kid in my lap.

Good reading:

https://www.google.com/url?sa=t&sou...FjATegQIBBAC&usg=AOvVaw2Im_aPk7M4rWA1y875vFx7

 

[thenightman]

Toyota calls it a multi-mode transfer case, not a locking center differential. The confusion is generated by owners hoping that they have something special and dealers advertising it as some kind of feature.

To be clear if I wasn't already, my gripe is that a lot of multi-mode owners, especially 01-02 guys for some reason, act like it's some rare thing or list it when they talk about their their trucks (I have an 02 with Center Locking Diff). All of the 4WD trucks in 01-02 came with it. It's literally part of the design. You couldn't buy one without it. They didn't make any with out it. It's literally the exact same transfer case as what came on the 99-00 Limited, they just moved a couple of buttons (and probably changed the 4WD comp and harness if we're being fair). The shift actuator, to my knowledge, is the only thing that changes between the two year ranges mechanically.

This isn't aimed at anyone, it just annoys me.

My gripe is essentially the same. Really, just my opinion, the '01-'02 are less cool (and obviously less capable) then the 00' and earlier, because the earlier subgens have the option of an actual locker. If you want an AWD case you can get a '00 or '99 limited, and a locker.

When the center is locked, it becomes as good as a normal tcase, not better.

If a center diff is where it's at, then why does everyone swap in a locking diff in the axles, and almost nobody swaps In an AWD system?

 

[tx_shooter]

Whoever said the center diff lock sucks is an idiot who doesn't know how drivetrains work. 4HI unlocked is the ideal mode for those conditions. Lock the center diff for the trickier stuff and you are golden.

Same. I was driving everywhere on the snow and mixed conditions around DFW all week. The "AWD" mode was great for this last weekend. I was lucky to put 4Season tires on the week prior to the snow moving in. Between the 4Runner and the tires I was having no problems getting around.

 

[jgue467]

...... not a locking center differential. The confusion is generated by owners hoping that they have something special..

It is a locking center diff, locks front to rear axles, is this Not True? Sure the front/rear wheels are not locked to each other on each axle, 2 more locking diffs is Better than the one center, of course it is! Would I like them, sure, do I need them? Not really. No rock crawler here but alot of sand, dirt, mud, small rock, cactus and so forth which is just as much fun to me anyway.

No one, not one soul on here said it is Special.

What I said and will continue to say is very, very simple.

It works in all My conditions despite what others have experienced, maybe something is wrong with theirs? Who know, who really cares, right?

We all have some special, its called a 3rd gen 4runner, can we agree on that?

 

[Bad Luck]

Thanks for this Bad Luck. I've read the T-case differences thread a few times and never understood this.

Given this, and since I have an '01, what is the benefit of having the drive shafts spin at different speeds?

Thanks BL and jgue467 for your comments on this topic.


Eddie

I'm late to the party, but the benefit of having the front and rear driveshafts spin at different speeds is for driving in mixed road conditions like raining or snow/ice with patches of pavement. It allows for you to not bind up the transfer case when you have good traction (which would happen if you drive it in 4HI locked on good traction surfaces like a dry street) but still allows the front axle to assist in moving the vehicle in slick conditions when the rear axle loses traction. It's a middle ground between 2wd and 4wd in a traditional transfer case.

I join in on that question also. I totally understood my 2000 with the jcase and rear locker, drove that for 5 years in heavy snow and ice.
Now my 2001 im still not sure when to lock the center diff. Im driving in snow and ice all the time ( Novemeber to April) and guess im just in AWD ? Guess I use it when IM slipping, but havent had that issue yet as I drive smart.

4HI/AWD should be used when there is a chance of low traction or mixed traction driving conditions. 4HI locked (center diff locked) should be used when there is low traction. If you drive in 4HI locked on a good traction surface it will bind the transfer case up when turning and has a good chance of causing transfer case problems

It seems like toyota using the words "diff lock" regarding the tcase causes a lot confusion for some people. I bet if you asked some which is more capable off road, a 2001 with a diff lock, or a 97 with a diff lock, they would consider them equally capable, because they both "have lockers". It would have been much clearer if they had only referred to these things as having a AWD mode and a 4x4 mode.

2001 with a diff lock is the center diff lock for the transfer case.
1997 with a diff lock is the rear diff lock. Much more capable than the 2001 that never came factory with a rear locker.

The the 4runner has an old fashioned center differential that basically an open differential in AWD so if both back tires start to slip, all the power is going to go to the rear and none to the front.

There is a power/torque split between the front and rear when in 4HI unlocked (AWD) that will send power to the axle with more traction. It will not send all the power to the axle with the least resistance. It more of functions as a limited slip differential than an open differential.

 

[TheSaturnV]

We just had a unusually big winter blast for our area. Having driven both my wife's Range Rover and my 3rd gen in it, I continue to rate our 4runners nothing short of spectacular on snow.

:thumb:

 

[JLTD]

the 5mph people make my blood BOIL, lemme tell ya :mad2::mad2:

Heck yeah...stay home.

 

[toyotaspeed90]

I find this thread entertaining, especially coming from the land cruiser world. Why does that matter, you ask?

In 1987 you could buy a landcruiser with a manual transmission and a 4wd selectable transfercase. In 1988 that option was partially gone - being automatic only and a high/low with 4wd button. In 1991 this changed to 4wd with a selectable high/low transfercase (full time 4wd)), as they called it) and a CDL switch o the dash. The CDL became integrated in 1993 when shifting to low and did away with the switch.

Why does this all matter?

A transfercase (ignoring when the front axles are or aren't locked in) that is like a J shift - has 2wd, 4hi, and 4lo. When you shift from 2wd into 4wd, you're making a mechanical connection front and rear. There's no "locker" needed.

In the full time 4wd Landcruisers that don't have ATRAC in hi, there is a viscous coupler that helps (some remove it) transfer power front to rear but act like an open differential. If you have 1 wheel on ice you may end up driving all power to the 1 wheel, even if in "4wd". Thisnis because like an open differential, power gets transferred to the wheel with the least traction. The locker in the transfercase is akin to putting a J shift into 4wd.


As for driving in the snow... our 3rd gen is good fun. MY 97 limited is slightly more fun than the 97 sr5 manual we had... simply because the rear locker on the limited is nice (but my limited is a 5sp with a J shift). If I want to go toss the truck around, which is well balanced and easily controlled in a slower 4wd drift, the 4Runner is great.

It doesn't hold a candle in confidence and simplicity that our old 2001 LX had (even with questionable Cooper tires) or our current 2011 LX on BFG A/T. This is only because in tricky spots I can use 4lo, high suspension (if needed) or even crawl control, and "manual" shifting. However once I get through the tricky spot 4hi and ATRAC just make it all too easy - especially when moving from well plowed to not well plowed roads. The only concern this has is it's weight...

 

[MTwEeZi]

I found with center diff locked it slid more, although more predictable when breaking traction. The AWD mode with VSC on was the safest mode for getting around. Would have been perfect with a rear LSD.

The real fun is in an icy parking lot in 2H with VSC off!

 

[spartacus]

With appropriate tires and a little experience the 3rd Gen is amazingly good in snow.

 

[MTwEeZi]

There is a power/torque split between the front and rear when in 4HI unlocked (AWD) that will send power to the axle with more traction. It will not send all the power to the axle with the least resistance. It more of functions as a limited slip differential than an open differential.

This is news to me! Do you have more info or a link?

 

[Bad Luck]

This is news to me! Do you have more info or a link?

I don't have any technical data, but confirmed it with ice this past week. Rear axle was spinning on ice and wouldn't gain traction so put it in 4HI (not locked) and was able to move forward. Rear tires still spun, but the front axle had enough traction to pull me off the ice.

 

[MTwEeZi]

I don't have any technical data, but confirmed it with ice this past week. Rear axle was spinning on ice and wouldn't gain traction so put it in 4HI (not locked) and was able to move forward. Rear tires still spun, but the front axle had enough traction to pull me off the ice.

Interesting; I did find this documentation on the multi-mode for those interested.

 

[thenightman]

On the road, in terrible weather, the AWD is really nice to have. Where I live we pretty much only get nice weather, so I use it mostly on trips or mountain passes. Of course, I decided to undo the advantages the AWD gives me several years ago by putting on aggressive mud tires. It's still better then not having it though.

 

[summcat]

Is there anything wrong with staying in AWD (button pressed on 99 Limited) full-time throughout the winter? I started by turning it on and off as needed, but wonder if the engage/disengage might be wearing on the vehicle more than the full-time engagement. Thoughts?

 

[alumarine]

Is there anything wrong with staying in AWD (button pressed on 99 Limited) full-time throughout the winter? I started by turning it on and off as needed, but wonder if the engage/disengage might be wearing on the vehicle more than the full-time engagement. Thoughts?

I would leave it on all winter especially if you have snow or some other slippery conditions.
I leave mine in 4wd all winter except if the streets get dry which is rare.