Problem with Auto 4wd

[cabikaze]

Nobody at the service or dealerships believe me or have heard of this problem. It is as if i have entered the Twilight Zone. The problem with my 2002 Qx4 which I purchased new is that it no longer feels the same when being driven in auto 4wd. Up to about 8 months ago with only about 42,000 miles on it, my wife and I could put it in Auto 4wd and it felt just like it was in 2wd until the wheels slipped or the conditions warranted it. Now, it feels like the truck is in 4wd in that it is less maneuverable and distinctly so. It used to be that you had to look at the console to even be aware. Now the service people are saying that it is performing exactly the way it was designed. Mind you the owner's manual states that when in Auto 4wd the car will be getting from 0-50% of the power to the front wheels depending on conditions. The diagnostics say nothing is wrong. What do other drivers of this car experience when the car is in Auto 4wd?

[KoukiS14]

Welcome to NICO!!My 99.5 is at 77k miles, and it feels just like I'm in 2wd until there is any sort of wheel slippage. I can go, turn, do whatever on bone dry pavement and I have absolutely no feelings of binding or any differences in driving than when it's in 2wd.

If it feels locked, something is def. not right, but I don't know what would cause it.

[bmlawless]

My '99 feels exactly the same in Auto and 2WD.

You can test it easily enough on dry pavement. Put it in Auto, turn the wheels all the way to one side and roll forward. If the vehicle "hops", then the front wheels are engaged and something is wrong. Put it in 2WD unless you are on slick surfaces and take it back to demonstrate.

If you are not sure what it should feel like, try the same test in 2WD and Lock and you will see the difference. You only want to do this for a second as part of the test. Don't do this a lot because it puts a lot of stress on the 4WD components.

Our vehicles have full-time hubs on the front wheels, so the only thing that engages the front wheels is the clutch in the differential. If it doesn't hop around in Auto, then the front wheels are rolling free and the system is working properly.

One last tip: Don't switch from Lock to Auto or 2WD while rolling with your wheels turned. When the front wheels release you'll get a big bang and a jolt. It doesn't hurt anything, but it'll scare you!

[Domenico]

On my 97 qx4 when i put it in auto it feels like its in 4wd even on hot sunny days..

[cabikaze]

I was told by the service manager at the dealership that it was "normal" for it to feel like it was at least "partly" in 4wd when it is in auto. When I pointed out that the owners manual stated that the auto position would direct power to the front wheels only when slippage was detected, he said the owners manual was incorrect. My point and what I am trying to correct is the notion that the car "feeling" like it is in 4wd while in auto is not something that is out of the ordinary. I know that the car did not do this until recently. I know it is a problem. Because the computer and the diagnostics do not show any problem, they are saying there is no reason for them to do anything. How do I convince them that the car is not right? Can I get some support from other owners saying that they do not get any of the 4wd noise or sluggishness or impaired turning when inauto on dry pavement?

[bmlawless]

Can I get some support from other owners saying that they do not get any of the 4wd noise or sluggishness or impaired turning when inauto on dry pavement?

I have a 1999 QX4 with 113,000 miles. I agree 100% with your statement regarding noise, sluggishness, and impaired turning. My vehicle behaves and feels exactly the same in Auto as it does in 2WD on dry roads.

[gwhunt23]

Someone posted a good diagram recently in another thread describing the Auto "slip-n-grip" AWD system, but I can't seem to find it.

The key point to keep in mind is that while in Auto, power is driven to the front wheels when starting from a stop (i.e. you're at a stoplight and hit the gas, the Auto system doesn't wait for slippage, it starts out in 4 wheel drive then adjusts after a certain speed.)

If you haven't already, it would be a good idea to change the Auto Transfer Case fluid. It simply takes Dexron III transmission fluid. I can email the section of the service manual describing how to do this if you wish - just let me know.

[KoukiS14]

GW -- This is good info. . I'm going to leave work here in a couple minutes and test this out.

[bmlawless]

The key point to keep in mind is that while in Auto, power is driven to the front wheels when starting from a stop (i.e. you're at a stoplight and hit the gas, the Auto system doesn't wait for slippage, it starts out in 4 wheel drive then adjusts after a certain speed.)

On one hand I buy this because I have noticed that I have instant 4WD from a stop and I never feel the front end kick in. On the other hand I have a hard time with the concept because there is no binding from a stop with the front wheels turned completely.

I am sure that the statement is a simplified version of the operation. I would love the see the full thread if someone finds it.

[KoukiS14]

I got to thinking about the "on from a stop thing". . I have to disagree, because when I take off hard from a stop on snow, rain, or other slick surfaces, the rear wheels spin from a dead stop for maybe 1/4 to a half turn, then stop as power goes to the front. . maybe like 1% 4wd is on from a stop. Also, I turned my wheels to lock and accelerated in auto last night, and I experienced no differences than when in 2wd -- the pavement was dry.

[SnowSurfLax]

Well, I gotta throw in my $.02...

Given the mass amoutns of rain we've had here lately, I've been doing a lot of jack rabbit starts in the rain to play with the AUTO function. I have to say I don't spin my tires at all when I hit hard from a stop when it's wet.

I also use that function when leaving the carwash (i've done some light drifting a couple of times) as my tires are soaked and I'm on smooth pavement with cars racing up over a hill at me.

So, who knows? Maybe the sensors dont' always know exactly how slippery it is.

[KoukiS14]

Or you have good tires. . I still have the dueler h/t tires on mine. . not needing to be replaced, but not in the best shape. . I can just about always get the tires spinning in both conditions.

I dunno. . it seems like we have two different viewpoints: auto that feels like 2wd and allows for a bit of slip, and auto that feels more like locked 4wd.

I don't think anyone is wrong necessarily, but mine does have a bit of latency if I break traction quickly.

The auto is exceptional for drifting around, since (at least in my case) works like 2wd for a split second, which happens to be juuuuust enough time to get the back end out before breaking the front tire traction, too sorry, I came from a 240sx, and all we do is slide around in those.

I really hope the awd in the G35x works exactly the same way. . I can't imagine what sort of fun that car will be (I'd like to think I'd enjoy one someday).

[bmlawless]

Just to clarify. On dry roads, I notice no difference between 2WD and Auto.

Dry pavement been the exception around here lately. For the most part I have been on snow and ice for the ast two weeks. Yesterday I was actually in an empty parking lot in front of a bank of windows and was able to watch the wheel spin in Auto vs. Lock.

The following procedure was performed prior to the first test and between each test:1) Place the vehicle in 2WD.2) Perform a U-turn.3) Drive approximately 50 yrds.4) Come to a complete stop and perform another U-turn.5) Come to a complete stop.6) Select appropriate drive mode and perform test indicated while driving in a straight line.

It was interesting.

From a stop with full throttle.LOCK: Slight spin (appeared to be less than 1 revolution) in rear then all four wheels spin simultaneously.AUTO: Same.

From a stop with half throttle.LOCK: Occasional slippage from all four wheels simultaneously.AUTO: Same.

From 10-15 MPH roll with full throttle:LOCK: Instant spin with all four wheels.AUTO: Significant spin (5-6 revolutions) in rear wheels before front wheels began to spin.

From 10-15 MPH roll with half throttle:LOCK: Very little spin from any wheels.AUTO: Some spin (1-2 revolutions) in rear wheels. Spin stopped and did not resume.

From 10-15 MPH roll with half throttle, then increasing rapidly to full throttle:LOCK: Very little spin from any wheels.AUTO: Some spin (1-2 revolutions) in rear wheels. Spin stopped and did not resume.

It was interesting to note that from a stop, the bahavior appeared to be identical to the LOCK behavior, but when moving, there was a noticable difference in the time it took to lock in the front end.

[KoukiS14]

Above and beyond, sir We're getting snow here this PM -- I'll test this myself, perhaps using a store window as a mirror so I can observe.

[cabikaze]

I appreciate everyone checking their vehicles and everything. However, I no longer doubt that the facts are clear. The car is not working the way it was when I bought it. As it is still under warranty, I just want Infinity/Nissan to take care of it. So far they have only said it is functioning as it should. I just ask that if you can agree to the following description you let me know: 1. The qx4 auto position indicates a mode in which power is distributed to the front wheels when conditions call for it. 2. In ideal conditions while set at AUTO there is no obvious or noticeable feeling of being in 4wd 3. The vehicle does not need to be shifted out of auto to avoid the binding feelind when making tight, slow turns.

If you do not agree with the three things above, then there is nothing you can do to help me. I am looking for some help. My car is not performing as it did for the last 5 years, and I just want to get it fixed but people who do not believe it needs fixing will not attempt it.

[KoukiS14]

1. Yes2. Yes3. Yes

[bmlawless]

1)Yes2)Yes3)Yes

[SnowSurfLax]

1) Y2) Y3) Y

Lawless - lucky dog. I miss those wide open parking lots covered in snow when I lived in ID. I learned to drive in that crap, so much fun!

I'd set up a rally track if I had my QX up there right now. Snow drifting!

Btw, you shoulda taken video of that test!!!