If You Have A 4x4, ?do You........

[Ahhnuld]

Ever hear any type of noise when the front axle is engaged like a slight gear whine, harmonics, or does it sound and feel exactly like you are still in 2x4 mode?

Ever have your Av pull at all to either side during ?acceleration?


I just had the pinion gear, bearing etc, replaced in my front axle, but the slight whine/ hum is still present, and I get ?a slight pull to the right when I accelerate hard. I am trying to determine if I have the makings of lemonade or if a lot of you hear/feel the same, and this is normal. Thanks for your feedback!

 

[gpfahler]

I have not had any of the symptoms that you have experienced. I recommend that you have a dealer look it over.

 

[wrchism]

Are you referring to 'auto' mode or 4-Hi?

I've not used 4WD much, but in auto mode I don't recall any different sound from 2-Hi. In 4-Hi (used on snowpack only a couple of times), there was a bit more mechanical noise, but nothing disturbing.

No pulling under accelleration, braking, etc. That seems expecially worrisome - I'd check it out.

 

[NJAV]

I have engaged the 4-hi and auto....and never had that happen...as a matter of fact I pretty much gunned it from a red light on a side street once in snow and felt no pulling at all.....

Just my head bouncing off the head rest...

 

[Clutter_Boy]

No pulling, just a small burning smell after it is engaged for awhile. Also, sometimes there is a slight "rubbing" noise, as if the tires are rubbing on the fenderwell.

 

[mike56BA]

When I have it in 'Auto' mode, I have a slight whine in the front end. When it's in 4 HI there is a growling noise when under acceleration. Took it to dealer and they said it was normal and there was a tsb on it. I think its a bit loud to be normal. Haven't noticed any pulling when accelerating.

 

[Ahhnuld]

mike56BA,
Finally! I find it hard to believe that all 86 readers of this post drive just the 2x4 Avs.

Thanks Mike for your answer. It sounds EXACTLY like mine, and I had the shop foreman ride with me from one dealer and he said the same thing about it being normal. When I took my Av in to a different dealer for a water leak issue, I asked them to check out the front end noise as well, just to see what they would say about it, and they called and told me they were replacing the pinion gears and bearings. That was nice, but the noise hasn't changed, so maybe it is normal. Keep me posted on your Av as far as if it gets worse or a shop does say that it is not normal. I won't be too concerned about it unless I get a substancial amount of feedback from other who have 4x4s and read this post. I am hoping they will either say yes they have some type of gear noise or no, none at all. That is why I posted this question, I would like a response.

 

[sinyster]

sounds to me like its not engaging completely, or that one side is and the other side isnt.. about the pulling it would seem likt its the one side and not the other engaging.. that would explain the pull, and to the other reader about the grind when turning... i was told that comes from the fact that the cv joints are actually delivering power to the wheels while turning... and if you turn the wheel had enough, you wil get a grinding noise like a tire rubbing on a fender. its no biggie.. if you dont like the noise, ususally you can just take shallower turns in a parking lot to avoid it... its a pain in the ass tho

 

[Chief]

Are you referring to 'auto' mode or 4-Hi?

I've not used 4WD much, but in auto mode I don't recall any different sound from 2-Hi. ?In 4-Hi (used on snowpack only a couple of times), there was a bit more mechanical noise, but nothing disturbing.

No pulling under accelleration, braking, etc. ?That seems expecially worrisome - I'd check it out.

Ditto - word for word including when I've used 4WD...

 

[nate]

From what I know about 4x4 versus AWD, what you are describing is normal. I only tested the 4x4 option last week when it snowed and yes, I *sense* a difference both in sound and feedback through the steering wheel.

It doesn't turn quite as smoothly either. From my understanding that is normal too. The front differential is powering the wheels at the same speed. Obviously when you go around a turn the outside wheel needs to spin faster then the inside wheel. This is what our systems is *fighting* so to speak. That is why the owners manual clearly states not to do normal driving in 4x4 mode. It will prematurely wear out the drivetrain. 4x4 mode in trucks is truly only useful for starting on a slippery surface. AWD uses LSDs to manage each wheel independently (and obviously there are some really sophisticated systems out there too). I experienced the same whining/feel in a friend's 4x4 Jeep Grand C. However in my 96 Mistubishi VR-4 (twin turbo, AWD sports car), there was no such problem. Nor with my dad's Subaru SVX (AWD GT).

That is all what I understand and I could be wrong.

Now something that is an [educated] guess as to the pulling to one side under hard accel. Torque steer. This happens in almost all front wheel drive cars, or at least those powerful enough to pull it off. The half shafts going from the front differential to the wheels are different lengths. As we learned in 10th grade physics, torque applied on a lever is multiplied by the lever's length. Our 4x4 systems I THINK have different length half-shafts up front. I could be wrong though and that is why I consider this a guess.

Nate

 

[Ahhnuld]

Nate,
You may be onto something. In fact, the distance from the right front wheel to the axle is farther than the left, as the drive shaft from the transfer case to the front axle is on the drivers side. The pull I feel is very slight, but at highway speeds, if I stomp on it and hold it, the truck wil change lanes if I let go of the steering wheel in about 4 seconds. Whe I get off the accelerator, the pull imediately stops and the truck track straight.

 

[j166a99]

hey, i just noticed this recently. i pushed my Autotrac button during a most recent rain storm, and forgot all about it.

during one of my accel. i noticed a bit of a whine, and it came to my immediate attention that the Auto button was still engaged.

so, i hit the 2WD button, and vwalla...instant cure!

 

[rockslide]

I've run my av in auto and 4hi not gently either (the snow can be real fun on them deserted roads) never heard any noise except for me screaming with joy