4WD noise

[Milkman]

Well,

after an exhaustive search on the forum, I would like to ask if anyone is still having 4 wheel HI humming noises coming from the drivetrain. I recently purchased my 2003 and since I live in Canada (land of snow and Polar bears ;) ) it has snowed the past few days and the roads are ice packed in my area. No big deal I thought and put my truck in 4Hi as I have in the past with my 4 other 4X4's. Everything was fine until I got up to about 90km/hr or so (roughly 50MPH) and then a God awful hum made me pull over and re-think my strategy. This time, while stopped I shifted the tranfer case (electronic jobby) back into 2HI and then back to 4HI. When I got up to the same speed, same thing happened.

Now the question. I read that some people had their transfer cases switched out of their truck and that seemed to cure the problem. Others have said it is in the driveline design.

Is there any new news or can anyone offer any advice on this problem? Where I live, I need 4X4 for about 70% of my winter driving. I have always travelled up to 110km/hr with all my other 4X4's without any problems. This is very concerning.

Thanks for anyone that can give me a hand with this.

Keith

[ 11-02-2002: Message edited by: Milkman ]</p>

[wxmn6]

Just for your information, you are supposed to shift between 2Hi and 4Hi while you are in motion, not stopped. Also I would never go over 50MPH if I need four wheel drive.

[Milkman]

Thank-you

The reason I stopped was partially to read the owners manual and see if I had done anything wrong. I did read however that you can shift into 4Hi "at any speed". We have a 4WD 3/4 ton Subuurban (emergency vehicle) which consistently goes over 120km/hr(70mph or so I think) and it is a 1996 with no problems. This is why I am so skeptical....

Keith

[dave p]

i had the same exact problem,dealer installed a new transfer case and it went away! dave p :cool:

[SoMnDMAX]

I've had the same problem with mine, and still do to some degree. The noise now @ 28K is about 10% of what it was when the truck was new.

[Milkman]

Thanks SomnDMAX and DaveP. Appreciate it. Maybe I will try to get the local dealer to install a new transfer case as well. I might stand a better chance kissing the Pope's toes but if you don't shoot you don't score!
Thanks again

Keith

[FstTrack]

I used my 4 wheel for the first time this weekend and had the same problem living in montana all of my vehicles are 4 wheel drive and the only time they make noise is when something wrong. The noise seemed to be less at 80mph than it is at 60 under load not so sure all the noise was from the transfer case. would be very iterested as to what you find.

[Milkman]

Thanks FstTrack. I will as soon as I get back home to my dealer. I would hate for them to start tearing it apart and have to keep it for the week. I am 600kms from home and it would be a long drive in my GM rental which would probably be a Cadillac Corolla! smile.gif smile.gif

[ 11-04-2002: Message edited by: Milkman ]</p>

[Milkman]

Update:

Took the truck to the dealer today. The service manager came out with me and does agree that the noise is too loud and has put a call into GM. I guess it's 25% of the battle right? I'll let everyone know what happens from here.

[FstTrack]

Milkman

How did the trip to the stealer workout I guess I should run mine in and see what they have to say.

[Milkman]

Well!

I just got my truck back after 2 days at the dealer. It turns out that the 4WD noise was in fact the front differential "grounding out" on one of the engine mounts. This was happening right in the middle at the very top of the differential as it was easily located once the teck took the diff out and showed me. There was a rub mark on the large white sticker located in the aforementioned location.
The dealer was not allowed to do anything with it for one full day until the GM engineers could figure out why a "cast" piece was in fact causing the problem. So the dealer took another identical '03 and took it for a spin then took the diff out as well. Even though there was something like 1/4 of an inch distance between the bracket and diff on that one, they never came into contact. According to GM I am one of a kind!! :rolleyes: (In North America anyways) All they ended up doing was grinding the excess weld material off of the mount and presto! No more noise!

Hope this helps!

Keith

[ 11-13-2002: Message edited by: Milkman ]</p>