-01 tahoe strange 4hi sounds

[daol]

hi, first snow is here, and first time really using 4hi, but Im getting really strange sounds from the front tires, not sure if something is wrong, or its because of how the 4wd system is designed.

the sound is hard to explain, but sort of squealing/grinding sound, but only at low speeds when turning, or braking to a standstill, the sound only starts below 12 mph or 20kmh, but no sound when taking off from standstill, even with hard acceleration with and without wheelspin, or cornering at moderate/highway speeds, also no sound when reversing, any idea?

 

[Fless]

Are you experiencing this on slick roads (snow, ice, etc.) or only on hard, clean pavement?

 

[daol]

atm we have snow covered roads, so yeah slick roads, havent used 4hi, since I got the car this summer, didnt hear the strange sound then

 

[rockola1971]

Drain the front dif and see if there are any magical metal surprises in there for you. Jack front wheels an inch off the ground and check hubs for bad bearings.

 

[daol]

my first thought was something is wrong with the dif, but then I started thinking, why do I only get the sound at low speeds, if something in the dif was broken/really worn, should I not hear it even more, when I accelerate hard, or turn hard, not just from 12mph or slower? was also thinking u joints, Im no mechanic, but it would make more sense if it was not just at low speeds, but Il try finding a mechanic that can look at it, but its hard, since the tahoe never was sold here officially, so most mechanics wont touch it, since there are no work descriptions in their systems for it.
did a test after my first post, a sharp corner, drove at 12mph, heard the sound, same corner at 20/40mph, not a sound.

 

[daol]

.

 

[Doubeleive]

i would say if there is no metal shavings in the fluid then I wouldn't worry about it being something wrong with the differential some of them are just noisy, you could try putting it up on 4 jack stands and put it in gear and see if you get the same noise.
one thing to consider also is how the 4wd system works, slow sharp turns are going make the front wheels bind against the rear, 4wd is designed to pull the front of truck left or right so it will make noise and you will feel it bind up on dry ground.

 

[daol]

hi, thanks for the reply, that was one of the things I was thinking about, that the sound could simply be because of how the 4wd system works, since its only at low speeds while turningin in roundabouts or intersections, or braking to a standstill at or under 12mph, and not a soúnd at normal/high speeds

 

[daol]

another question, other then the obvious, are there any other differences between 4hi/auto,in how the system works, other then that 4hi is 4wd all the time? tried using "auto" and I dont get that strange sound, even when I can feel the front tires working, and Im not going sideways like in rwd , but when I shift back to 4hi, I get the sound

 

[rockola1971]

4 auto uses clutches in the tcase so the front can be disengaged/engaged automatically. In 4wd the front axles are engaged the whole time and there is no slip within the tcase for the front.