AWD transfer case noise

[teamjnz]

Few few weeks ago I purchased a 2004 Tahoe with the AWD system, 150,*** mileage. It doesn't have the 2Hi button.
Quickly after the purchase I had 4:10 gears and a TruTrac type of rear differential installed with new bearings and seals put in. Basically had the axles rebuilt. It has 33" tires and when they wear out I probably will install 35s.
Yesterday was the first real road trip v.s. commuting back and forth to work, low speed.
On the highway cruising at 70 when there is load on the drive train there is no noise. Deceleration with some load on the drive train there is no noise.
There IS noise when cruising with no drive train load like when there is a slight decline in the road and coasting.
It sounds like chain slop or gear chattering maybe bearings. The noise is coming from under the truck.
The RPO is NR4 which I believe is the BW4482 transfer case.
Any suggestions or experience?
Would this be a good time to replace and upgrade the t-case or just rebuild it?
I want to use the truck for overlanding, not heavy 4x4ing or obstacle driving and curious if keeping BW4482 is the best for my plans or is there a better option.
Thanks

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

Since you state that you have an AWD drivetrain on your truck, there is no 2Hi button, nor is there any 4x4 activity, per se.

I recommend that you take the truck to a trusted local repair shop, and get the truck on a lift with the wheels off the ground and with someone inside the truck. Put the truck in gear and press the gas pedal to get the wheels turning, and see if the noise also occurs in different situations of loaded and unloaded (wheels off the ground). If the noise still occurs, then the Mechanic underneath the truck can go around, with a stethoscope if necessary, and locate the source of the noise.

If it turns out that the noise is coming from under the mid section of your truck, it is most likely the transfer case. But, the sound that you describe, except for the chain slop noise that you hear, sounds more like a rear differential type of issue. The chain slop noise would suggest the transfer case, though, as it has an interior chain.

If it turns out to be the transfer case, you can purchase a used one with a 1 year warranty for under $400 delivered from LKQ. This is what I did, and I had it delivered directly to my gear builder, who just completed a complete rebuild on it, since I am refreshing my entire drivetrain, one component at a time.

 

[teamjnz]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

Since you state that you have an AWD drivetrain on your truck, there is no 2Hi button, nor is there any 4x4 activity, per se.

I recommend that you take the truck to a trusted local repair shop, and get the truck on a lift with the wheels off the ground and with someone inside the truck. Put the truck in gear and press the gas pedal to get the wheels turning, and see if the noise also occurs in different situations of loaded and unloaded (wheels off the ground). If the noise still occurs, then the Mechanic underneath the truck can go around, with a stethoscope if necessary, and locate the source of the noise.

If it turns out that the noise is coming from under the mid section of your truck, it is most likely the transfer case. But, the sound that you describe, except for the chain slop noise that you hear, sounds more like a rear differential type of issue. The chain slop noise would suggest the transfer case, though, as it has an interior chain.

If it turns out to be the transfer case, you can purchase a used one with a 1 year warranty for under $400 delivered from LKQ. This is what I did, and I had it delivered directly to my gear builder, who just completed a complete rebuild on it, since I am refreshing my entire drivetrain, one component at a time.

Thanks for your input on this. I think taking it to a shop is safer than putting it up jack stands, putting it in gear and crawling under it to listen for the noises.