4wd Noise

mdsilver · January 8, 2010

truck has just over 10k miles on it. This the 2nd winter for this truck and I noticed a grinding noise which appears to be coming from the transfer case. Its not the normal sound you get while in 4WD. I had this truck in the snow last year. Also this is my 5th 4WD gm truck i've owned so i'm familiar with all the normal howling/ grinding, etc noises. Oddly enough i get a similiar noise when applying brake (no it is not abs sound). All this happens while city driving on snow/ice roads. Noise does go up w/ engine rpm. Anyone experience this - or am i just going crazy. By the way, it is 4.8litre w/ on the floor 4wd shift.

mdsilver · January 8, 2010

i forgot to mention the obvious - noise does not exist while in 2WD.

csheatz · January 8, 2010

something with the shaft from the transfer case to the front end? does that shaft have joint in it? i can remember off the top of my head

C. Charles Hahn · January 8, 2010

something with the shaft from the transfer case to the front end? does that shaft have joint in it? i can remember off the top of my head

There are u-joints, but it's still just a one piece driveshaft.

Since it's a manual shifting transfer case, I have to wonder if maybe the lever isn't engaging the t-case all the way or just isn't locking into position properly.

Does the noise happen in both 4HI AND 4LO, or just 4HI?

pm26 · January 8, 2010

Sounds like the linkage problem from the lever to the transfer case.

mdsilver · January 8, 2010

something with the shaft from the transfer case to the front end? does that shaft have joint in it? i can remember off the top of my head

There are u-joints, but it's still just a one piece driveshaft.

Since it's a manual shifting transfer case, I have to wonder if maybe the lever isn't engaging the t-case all the way or just isn't locking into position properly.

Does the noise happen in both 4HI AND 4LO, or just 4HI?

I haven't tried in 4LO yet. 4wd works fine so I'm just going to run it and bring it in after winter. Unless the noise gets worse.

Nytemare · January 8, 2010

Its obviously coming from the muffler bearing....

If you want a better diagnosis....bring it in to the dealership where they honor this wonderful thing called a warranty...you take the service manager or mechanic out for a drive and let them hear the noise...than they look at what they think it is and come back to you telling you it was a wappaty splash that was stuck in the metrickulator and your on your way...no guessing...no bad advice and best of all...no money out of your pocket.

C. Charles Hahn · January 9, 2010

I haven't tried in 4LO yet. 4wd works fine so I'm just going to run it and bring it in after winter. Unless the noise gets worse.

What kind of mentality is that? You don't know what the problem is, it could be causing further damage by just 'running it' as is.

mdsilver · January 12, 2010

I haven't tried in 4LO yet. 4wd works fine so I'm just going to run it and bring it in after winter. Unless the noise gets worse.

What kind of mentality is that? You don't know what the problem is, it could be causing further damage by just 'running it' as is.

Mentality of someone who needs his truck to get to work in the winter but does not have time to mess w/ the dealership. I understand it is under warranty and I'm sure GM will honor it. I just thought I would post to get some thoughts on how serious it is. Also, if you read the thread there is not an issue while in 2WD.

I do agree that it needs to go to the dealership. Hopefully soon... perhaps I can get the those 'muffler bearings' serviced!

Nytemare · January 12, 2010

I haven't tried in 4LO yet. 4wd works fine so I'm just going to run it and bring it in after winter. Unless the noise gets worse.

What kind of mentality is that? You don't know what the problem is, it could be causing further damage by just 'running it' as is.

Mentality of someone who needs his truck to get to work in the winter but does not have time to mess w/ the dealership. I understand it is under warranty and I'm sure GM will honor it. I just thought I would post to get some thoughts on how serious it is. Also, if you read the thread there is not an issue while in 2WD.

I do agree that it needs to go to the dealership. Hopefully soon... perhaps I can get the those 'muffler bearings' serviced!

Just cause you cant hear anything going on in 2wd doesn't mean nothing is getting damaged in 2wd. If you absolutely need a vehicle, and you kick up enough stink at the dealership...they will get you one.