Is this a Major Problem?

[T4R4TR]

I've had my '08 Urban Runner for five days now. I went out to some muddy roads the other day to test out the 4wd and locking differential to make sure that they worked appropriately. I did engage and disengage the 4hi, 4lo and center locking differential while test driving the vehicle but could not do much other than make sure they engaged and disengaged smoothly.

So here is what I am concerned is a major problem. I was trying to reverse up a steep muddy hill. The 4runner was in a position where the rear driver side wheel was almost completely off of the ground. I was in 4hi with the center differential locked. I was unable to reverse up the hill and the wheel that had no weight on it began to spin while the others were not. When this happened, I heard some awful slipping or grinding noises in the drive train. I immediately let off of the gas and stopped trying to back up. What was happening? I was under the impression that all four tires should have been locked together and that no one wheel would spin more than the others. Do I have a bad or slipping center differential?

If this is a major problem, I assume that the vehicle being 5 days old and certified pre-owned, the dealer should take care of it with little fuss.

Any thoughts?

 

[wombie]

As to whether there is a problem with your diff lock, I am not sure - I'll leave that to the off road experts.

As to the Certified warranty - it's pretty much bumper to bumper so if you have any trouble with the truck take it back. If you don't like what the dealer says then take it to a different one or just call Toyota corporate.

 

[settytb]

It is the ABS system trying to apply the brake to that one wheel so it can transfer power to the other one with traction. When the wheels start to slip there is all kinds of weird noises that happen but rest easy it's just the abs doing it's thing nothing to be worried about.

 

[T4R4TR]

Though I was not 100% sure, I thought that with the center differential locked that all four wheels had to move at the same speed. I guess this is not the case?

 

[Acidmeld]

With the center diff locked the front and rear driveshafts are locked together. The front and rear diffs are still open so the wheel off the ground will still spin. The noise was the abs kicking in to stop the spinning wheel.

 

[Jerrydog]

Though I was not 100% sure, I thought that with the center differential locked that all four wheels had to move at the same speed. I guess this is not the case?

The center diff is a major dissapointment I thought the same thing and the salesman touted it as you suggest. If you are used to standard 4x4's all it does is make the 4runner a standard 4x4 unlike an axle diff lock that when engaged locks the wheels together and if you have two you get actual 4x4 4 wheel, wheel spin.

I also loathe the anti wheel spin systems they have almost gotten me killed a few times in traffic.

Wait for an opeing in traffic
Goose it to pull out
one wheel spins on some sand, car lurches forward 5 feet
throttle dissapears
brakes apply
traffic brakes hard not to hit you
computer thinks about giving you throttle back
eventually you get trottle back as traffic stops 2 feet from your front fender and horns blair.
Curse and remember how your previous SUV you drove for 13 years never did that to you.....

 

[d2huffman]

I agree that the 1st time you experience the traction control (ABS) system working when in slick slow travel mode it is a little stange - it works if you give it a chance. While locking diffs are great for hard core off road, this system will provide everything the aveage off roader needs. I suggest playing with it a few times in mud/slick conditions to get the feel.
Regarding the traction control system and entering traffic - you have to be punching it way to hard to cause an issue. If you accererate quickly (don't stomp on it) and feather the throttle if needed you should be able to be in control. With out the traction control you would be spinning 1 tire and going oh s___t.

 

[MICA4R]

The center diff is a major dissapointment I thought the same thing and the salesman touted it as you suggest. If you are used to standard 4x4's all it does is make the 4runner a standard 4x4 unlike an axle diff lock that when engaged locks the wheels together and if you have two you get actual 4x4 4 wheel, wheel spin.

I also loathe the anti wheel spin systems they have almost gotten me killed a few times in traffic.

Wait for an opeing in traffic
Goose it to pull out
one wheel spins on some sand, car lurches forward 5 feet
throttle dissapears
brakes apply
traffic brakes hard not to hit you
computer thinks about giving you throttle back
eventually you get trottle back as traffic stops 2 feet from your front fender and horns blair.
Curse and remember how your previous SUV you drove for 13 years never did that to you.....

x2

the 94 runner will slip and then let me go... the :uzi: 08 is like you mentioned above: kindergarten and you lose your crayon privileges...

if there is even a drop of precipitation in the forecast or any sign or gravel or sand, the FIRST thing I do is turn off VSCrap.

 

[thirstyturtle]

It's just ATRAC bro, no worries at all. It's the same idea as ABS and it can individually flux the brakes on each wheel to overcome having open front and rear differentials. I HATE how loud and horrible it sounds, but it gets the job done fo sho. I got through some stuff because of ATRAC that my friend's Tacoma could not and he had a bigger lift and better tires. I like it.

 

[d2huffman]

I had limited slip rear diff on previous vehicles and that is not nearly as reliable as the ATRAC system - and it was no help on front end as this system is. I had a Matrix with the traction control - front drive only - and that would spin and fall off on power if you stood on it, but with decent tires on my t4r I have not had that problem. and driving sencibaly. If you are in slick conditions, put it in 4H and don't worry. Now if you purchase one of the vehicles with the vcs type differencials front and rear - then you don't have to worry either.