Possible transfer case noise

[Douglas Friedberg]

2006 Yukon xl 4 wheel drive with auto button 250,000 miles 5.3
While taking off in 2 wheel drive once in a while I hear a sound from system that sounds like a chain slipping on a bicycle derailed 10 speed switching gears. Something getting sloppy ? That sound is telling me something is going
To go wrong.

 

[Scottydoggs]

might be the rear diff going bad.

 

[Bill 1960]

Could be the chain hitting the case. That happens with excessive wear or loose chains.

Do you feel any jerkiness or hesitation, or is it just a sound?

 

[Fless]

You could get it up on a lift or jackstands and use a mechanic's stethoscope to narrow it down.

 

[Douglas Friedberg]

You could get it up on a lift or jackstands and use a mechanic's stethoscope to narrow it down.

J

Could be the chain hitting the case. That happens with excessive wear or loose chains.

Do you feel any jerkiness or hesitation, or is it just a sound?

 

[Douglas Friedberg]

Just like a bicycle chain derailer chain skipping the sprocket during gear changes on a bike. Yes jerking and slight hesitations then goes away. Doesn’t happen all the time. Domes traction code flashes on dash panel then goes away. Was afraid of this outcome. So there’s a chain in transfer case. Like old olds front wheel drive trans shit out of luck time i guess.
Bad part about 250,000 miles I guess.

 

[Douglas Friedberg]

Just like a bicycle chain derailer chain skipping the sprocket during gear changes on a bike. Yes jerking and slight hesitations then goes away. Doesn’t happen all the time. Domes traction code flashes on dash panel then goes away. Was afraid of this outcome. So there’s a chain in transfer case. Like old olds front wheel drive trans shit out of luck time i guess.
Bad part about 250,000 miles I guess.

How much time do I have left ????

 

[Douglas Friedberg]

How much time do I have left ????

Is this chain problem what causes the transfer case leaks I’ve been reading about???

 

[Bill 1960]

It might be worth paying a shop to put it on a lift and diagnose it, as @Fless recommended.

Going by the noise you describe, and the mileage, a worn chain would be expected. And yes, it can wear through the case and cause a leak, or it may just break and break the housing.

But- it’s possible it’s something in the rear end. There should be no pressure on the chain in 2WD.

Draining the oil from the transfer case would give you some idea of it’s condition. Likewise it’s an easy driveway job to remove the rear differential cover for an inspection. Or a few minutes on a lift with a stethoscope.

I wouldn’t drive it at all or minimally until it’s fixed. Could go bang at any minute and leave you stranded.

 

[Douglas Friedberg]

been

It might be worth paying a shop to put it on a lift and diagnose it, as @Fless recommended.

Going by the noise you describe, and the mileage, a worn chain would be expected. And yes, it can wear through the case and cause a leak, or it may just break and break the housing.

But- it’s possible it’s something in the rear end. There should be no pressure on the chain in 2WD.

Draining the oil from the transfer case would give you some idea of it’s condition. Likewise it’s an easy driveway job to remove the rear differential cover for an inspection. Or a few minutes on a lift with a stethoscope.

I wouldn’t drive it at all or minimally until it’s fixed. Could go bang at any minute and leave you stranded.

 

[Douglas Friedberg]

So is the chain relied on even in 2 WD as well ??
Rear end was done awhile back.

 

[Douglas Friedberg]

So is the chain relied on even in 2 WD as well ??
Rear end was done awhile back.

Thanks for the info people.

 

[Douglas Friedberg]

The other thought I was thinking aware of this noise is it sounds similar to when you are moving in neutral at Agee mph when changing to 4 wheel drive manually.
Could this be Servo motor screwing up trying to change mode on its own? Only happens when you start to move forward ???

 

[rockola1971]

https://atracom.blob.core.windows.net/gears/2006/2006-07/2006_07_10.pdf NVG246 Tcase operation. That chain may have already ruined your Tcase. It will eventually rip through the case body and destroy it without prejudice. My wife's 2003 did that and I had to find a core and rebuild it. The infamous pump rub leaked all the fluid out over time and thats all she wrote.

 

[Douglas Friedberg]

I drained the transfer case oil and refilled it. Nothing seemed out of place.

 

[Bill 1960]

Just like a bicycle chain derailer chain skipping the sprocket during gear changes on a bike. Yes jerking and slight hesitations then goes away. Doesn’t happen all the time. Domes traction code flashes on dash panel then goes away. Was afraid of this outcome. So there’s a chain in transfer case. Like old olds front wheel drive trans shit out of luck time i guess.
Bad part about 250,000 miles I guess.

I just read this, and your response today about the oil change. You may just have a malfunction in the traction control. Bad sensor for wheel or shaft speed.

Are you familiar with the feeling from traction control activation? It can cut engine power; use the ABS to apply brakes to individual wheels, and make a jerky feel in the vehicle, along with the attendant noises from the brakes and pump.

 

[Douglas Friedberg]

I just read this, and your response today about the oil change. You may just have a malfunction in the traction control. Bad sensor for wheel or shaft speed.

Are you familiar with the feeling from traction control activation? It can cut engine power; use the ABS to apply brakes to individual wheels, and make a jerky feel in the vehicle, along with the attendant noises from the brakes and pump.

Yes something is going on there because along with this comes traction message and gas pedal not responding to foot control pressure. I think that seems to me pedal control is removed by system when it sences traction problems but this all happens only on take off or starting out from a stop.

 

[Douglas Friedberg]

Yes something is going on there because along with this comes traction message and gas pedal not responding to foot control pressure. I think that seems to me pedal control is removed by system when it sences traction problems but this all happens only on take off or starting out from a stop.

Traction message only appears for a few seconds then goes away. I am not formilure with this computer system. Just old world 4 wheel drive. I tried pushing button on dash to disingage system to see if that helps but have not concurred results test Happens cold or hot doesn’t mstter

 

[Douglas Friedberg]

Traction message only appears for a few seconds then goes away. I am not formilure with this computer system. Just old world 4 wheel drive. I tried pushing button on dash to disingage system to see if that helps but have not concurred results test Happens cold or hot doesn’t mstter

To my ears and feel it seems like system is in the middle of going between changes from 2 wheel and 4 wheel or thinks it’s on ice.

 

[Douglas Friedberg]

To my ears and feel it seems like system is in the middle of going between changes from 2 wheel and 4 wheel or thinks it’s on ice.

Other then that vehicle drives normally with no sounds of anything is wrong