Ack! That grinding sound :(

[mishalah]

My 2005 1500LT:

I followed the manual instructions to a "T". My ops manual says in order to put the transfer case into "Neutral" you on my AWD setup I should start the engine, place the tranny in neutral, press the "low drive" and "StabiliTrak" buttons at the same time and hold for 10 seconds until the "Neutral" light comes on. Then....make sure the tranny was in neutral by shifting into reverse for a second or two, then into drive for a second or two...then into park.

I did all that exactly as required. But when I pushed the lever over to Park I heard this horrible clashing/grinding sound. Only about 1-2 seconds worth, but a nasty sound at that. I just let it idle, then shut it down (the little "Neutral" light stayed on.

What the heck did I hear...and was it actually supposed to do that just to get the transfer case into Neutral? I was in my driveway on a slight incline, but I held my foot on the brake the whole time in addition to having the e-brake on as required.

[mishalah]

OK.....crickets chirping here.

Maybe you can explain how this system works. I tried to put the transfer case in neutral, following the instructions in the opmanual. It did go into neutral with some disturbing noises, but when I tried to drive the truck the tranny wouldn't shift into either reverse or forward. I put it back into AWD as per the manual, drove it around the block a few times, and then put the transfer case into neutral again. And again, no forward or reverse from the main tranny.

Is this how it's supposed to work? The book says it is supposed to be used during towing or driving where the tires might slip and spin. So, why don't I get any movement at all? I can definitely hear the mechanism changing from whatever "drive status" it's normally in to the neutral status....and back out.

[777stickman]

Originally Posted by mishalah

OK.....crickets chirping here.

Maybe you can explain how this system works. I tried to put the transfer case in neutral, following the instructions in the opmanual. It did go into neutral with some disturbing noises, but when I tried to drive the truck the tranny wouldn't shift into either reverse or forward. I put it back into AWD as per the manual, drove it around the block a few times, and then put the transfer case into neutral again. And again, no forward or reverse from the main tranny.

Is this how it's supposed to work? The book says it is supposed to be used during towing or driving where the tires might slip and spin. So, why don't I get any movement at all? I can definitely hear the mechanism changing from whatever "drive status" it's normally in to the neutral status....and back out.

Why in the h**l are you putting the t-case in neutral?? Doing this is like taking the drive shaft out and trying to go for a drive!! Is this some kind of a joke post??

[j cAT]

Originally Posted by mishalah

OK.....crickets chirping here.

Maybe you can explain how this system works. I tried to put the transfer case in neutral, following the instructions in the opmanual. It did go into neutral with some disturbing noises, but when I tried to drive the truck the tranny wouldn't shift into either reverse or forward. I put it back into AWD as per the manual, drove it around the block a few times, and then put the transfer case into neutral again. And again, no forward or reverse from the main tranny.

Is this how it's supposed to work? The book says it is supposed to be used during towing or driving where the tires might slip and spin. So, why don't I get any movement at all? I can definitely hear the mechanism changing from whatever "drive status" it's normally in to the neutral status....and back out.

I put my 2000 silverado into neutral 12 years ago just to see if it worked. that was the last time I did this .

neutral is for towing the vehicle for a long distance. this will not provide any power to the wheels.

like is was stated , The effect is , your removing the drive shafts when doing this .

[mishalah]

Originally Posted by 777stickman

Why in the h**l are you putting the t-case in neutral?? Doing this is like taking the drive shaft out and trying to go for a drive!! Is this some kind of a joke post??

1- because the manual says I can AND SHOULD for either towing or driving on surfaces where the wheels might slip or spin.

2- because I want to see if not having the front drive unit constantly engaged will stop or diminish the subtle growling I can hear.

Putting the transfer case in neutral should not do anything except disengage the front drive and leave the rear drive working.....according the the GM MANUAL for this vehicle.

Hardly a joke.

[j cAT]

Originally Posted by mishalah

1- because the manual says I can AND SHOULD for either towing or driving on surfaces where the wheels might slip or spin.

2- because I want to see if not having the front drive unit constantly engaged will stop or diminish the subtle growling I can hear.

Putting the transfer case in neutral should not do anything except disengage the front drive and leave the rear drive working.....according the the GM MANUAL for this vehicle.

Hardly a joke.

so the manaul states if the vehicle is on a slippery surface disengagement of the front drive axle will improve traction and control ?

my experience is that is very much not true.

placing the transfercase in neutral would mean no drive connection to the wheels. towing with the wheels rotating the transmission does do some damage especially on the hywy .things heat up , no fluid circulating ..

If indeed this neutral with this vehicle ,it is still connecting the rear wheels to the tranmission.

so your issue with this vehicle is a growl type noise ?

are all the tires the same age/wear ? do you rotate the tires every 15,ooomi. ??? how often do you service the transfercase/front/rear diff fluids ? do you check these at every oil change for color and level ?

could be you do have drivetrain wear/damage making the noise.

[mishalah]

Originally Posted by j cAT

so the manaul states if the vehicle is on a slippery surface disengagement of the front drive axle will improve traction and control ?

my experience is that is very much not true.

I know. I don't understand their reasoning, either, but they are adamant about switching if the wheels could slip or spin in mud, snow, or off-road. So, what is th epirpose of AWD if not to give better traction?

placing the transfercase in neutral would mean no drive connection to the wheels. towing with the wheels rotating the transmission does do some damage especially on the hywy .things heat up , no fluid circulating ..

According to the manual, placing the transfer case in neutral should disengage ONLY the front driveshaft so that ONLY the rear wheels will have power (whether for towing or all those other restrictions just mentioned). It does NOT say that I should also use the "tow mode switch" ti insure a change in the shift points of the tranny. I wonder about that, too, but not all these subs have the tow pkg switch.


If indeed this neutral with this vehicle ,it is still connecting the rear wheels to the tranmission.

so your issue with this vehicle is a growl type noise ?

are all the tires the same age/wear ? do you rotate the tires every 15,ooomi. ??? how often do you service the transfercase/front/rear diff fluids ? do you check these at every oil change for color and level ?

Tires are almost new Michelins with about 1500 miles on them. All drivetrain fluids were changed about 10,000 miles ago, and the low growl from the front (I assume it's the front differential) has been there since I bought it...about 11K miles ago). I could have worn bearings in there, which is why I would like to disengage the front drive. But that should be accomplished by the opmanual instructions I used.

could be you do have drivetrain wear/damage making the noise.

enter as posted.

[777stickman]

Originally Posted by mishalah

My 2005 1500LT:

I followed the manual instructions to a "T". My ops manual says in order to put the transfer case into "Neutral" you on my AWD setup I should start the engine, place the tranny in neutral, press the "low drive" and "StabiliTrak" buttons at the same time and hold for 10 seconds until the "Neutral" light comes on. Then....make sure the tranny was in neutral by shifting into reverse for a second or two, then into drive for a second or two...then into park.

I did all that exactly as required. But when I pushed the lever over to Park I heard this horrible clashing/grinding sound. Only about 1-2 seconds worth, but a nasty sound at that. I just let it idle, then shut it down (the little "Neutral" light stayed on.

What the heck did I hear...and was it actually supposed to do that just to get the transfer case into Neutral? I was in my driveway on a slight incline, but I held my foot on the brake the whole time in addition to having the e-brake on as required.

OK, I'll try to be more tolerant (though I'm still shaking my head). No Joke!!

What happens when you put the tranny in park or neutral and rev the motor? You don't go any where. Same thing with a standard tranny. Put it in neutral, let the clutch out and go no where.

Same thing with a t-case. Put it in neutral, then go to drive or reverse and where did you go? No where!!

Now to the "grinding noise". With the t-case in neutral, you put the tranny in D & R then to Park, with the motor running. What happens is the tranny is internally rotating power from the output shaft to the t-case, which is in neutral and not putting power to the drive train. The "grinding noise" you heard was the internal tranny "park pawl" looking for a "park" slot to fall into because the output shaft thought is was driving the wheels and it wasn't. Sure hope you didn't break it. No Joke!!

[j cAT]

Originally Posted by 777stickman

OK, I'll try to be more tolerant (though I'm still shaking my head). No Joke!!

Now to the "grinding noise". With the t-case in neutral, you put the tranny in D & R then to Park, with the motor running. What happens is the tranny is internally rotating power from the output shaft to the t-case, which is in neutral and not putting power to the drive train. The "grinding noise" you heard was the internal tranny "park pawl" looking for a "park" slot to fall into because the output shaft thought is was driving the wheels and it wasn't. Sure hope you didn't break it. No Joke!!

that is what I was thinking ! placing the transmission in gear with the engine running would cause the movement of the internal gears , then placing into park the pawl would make noise trying to lock the moving gears internal of the transmission.

[j cAT]

check the fluid condition of the front differential. see if its gray color. if the fluid looks good , then I would suspect the rotational front grinding to be the front hubs/bearings..

[mishalah]

Originally Posted by j cAT

that is what I was thinking ! placing the transmission in gear with the engine running would cause the movement of the internal gears , then placing into park the pawl would make noise trying to lock the moving gears internal of the transmission.

dO YOU THINK gm WOULD REIMBURSE ME FOR ANY tc OR TRANNY OR FRONT DIFFERENTIAL DAMAGE ....oops...since I am doing it exactly as they tell me in their manual? Yeah, right. I wonder how many others have run into this.

[mishalah]

Originally Posted by j cAT

check the fluid condition of the front differential. see if its gray color. if the fluid looks good , then I would suspect the rotational front grinding to be the front hubs/bearings..

Yes, I will do this asap. THNKS

[mishalah]

Originally Posted by j cAT

check the fluid condition of the front differential. see if its gray color. if the fluid looks good , then I would suspect the rotational front grinding to be the front hubs/bearings..

I had the fluid checked today....dark gray. Dunno how "dark" as it was checked at Terrible's after getting it smogged. I got an answer from a member who had the same noise symptoms and he needed his bearings replaced. Kinda sounds like it. One thing after another.

[Alice]

This might help maybe not. I had a grinding or what sounded like someone dragging a chain over metal. It would happen on ice, fast take offs... sounded awful. Everyone said I needed a transfer case rebuild. Well someone under it one day noticed my small u-joint needed replacing. (there is two shafts the main drive and a smaller on a 4X4 right) Well, when they went to take the small driveshaft off, they noticed it was froze up, rusted in place when it is supposed to move. So I replaced that shaft ($500) and the little u-joint for it. Of course I thought I still needed a transfer case rebuild BUT... I never got that noise again. Must have been that little drive shaft. Just thought I'd mention it for so many people said it was my transfer case.

[mishalah]

Thanks, Alice. I'll have it looked at.