Bravada AWD driveline clunk

01silverado2500 · May 2, 2005

I have a 03 Bravada AWD and I have noticed a "clunk" sometimes during acceleration from a stop. The clunk can be felt in the steering wheel, most noticeably during heavy acceleration and it clunks a few times. I had the steering wheel binding and chutter tsb fixed after a few thousand miles and was wondering if maybe the two problems were related? Any tech info on my "clunk" problem is greatly appreciated.

MuranoSE · May 7, 2005

I have a 03 Bravada AWD and I have noticed a "clunk" sometimes during acceleration from a stop. The clunk can be felt in the steering wheel, most noticeably during heavy acceleration and it clunks a few times. I had the steering wheel binding and chutter tsb fixed after a few thousand miles and was wondering if maybe the two problems were related? Any tech info on my "clunk" problem is greatly appreciated.

<{POST_SNAPBACK}>

It's funny that you mention that because I have the same issue in my 04 Bravada. Everytime I accelerate hard it clunks a few times while going thrugh first gear. After first the clunking stops. I have an appointment with my dealer next week about it.

Also you mention the TSB that fixed your binding problem. You don't happen to know the number by chance do you? I have this problem and they said it was due to me having an AWD vehicle, but sometimes the binding is so bad that the vehicle will not move.

01silverado2500 · May 8, 2005

Well let me know what the dealer says. My clunking also goes away but it bothers me some.

OK here is what I found about the front end shutter.

This is my service record from the dealer..........im not sure of the TSB #

Repair Order- Customer states front end binding when turning.

Transfer case encoder motor(position sensor) defective

Replace position sensor

#K4124 Time 0.9 hours

Part # or description

88996635- motor trans. case encoder $42.40

88996636- gasket $21.01

12378508- Auto trrac II transfer $6.96

Also here is what GM-Tech said about the AWD in our Bravys

I'm not aware of any clunking issues like you describe. Without experiencing it, I couldn't even guess what it might be.

As for your 4wd system, it's full-time all wheel drive. Here's the "official" description of its operation, though it might be a little technical.

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The New Venture Gear model NVG 126 RPO NP4 transfer case is a one speed automatic, active, transfer case. The NVG 126 provides only one mode, Auto 4WD, and is transparent to the operator. The active transfer case provides the benefits of on-demand torque biasing, wet clutch and easy vehicle tuning through software calibrations. The software calibrations allow more features, such as flexible adapt ready position and clutch pre-load torque levels. The technology allows for vehicle speed dependent clutch torque levels to enhance the performance of the system. For example, the system is calibrated to provide 0-7 N·m (0-62 lb in) of clutch torque during low speed, low engine torque operation, and predetermined higher torque for 32 km/h (20 mph) and greater. This prevents crow-hop and binding at low speeds, and provides higher torque biases at higher vehicle speeds, to enhance stability.

MuranoSE · May 19, 2005

Well my vehicle has been at the dealer for a little over a week now. When they were testing the vehicle the found the "driveline" clunk was due to a faulty transfer case, and they are replacing the entire drive shaft from from front to back under warrenty. Also they are replacing my steering rack and transmission. It's a HUGE work order and would notmally make me worry but thankfully this is a leased vehicle and will be going back to the dealer when it's up.

01silverado2500 · May 19, 2005

I dont like the sound of that. Well when I take mine for an oil change Ill mention the clunk and see what they say. Thankfuly I have the 5year warrenty that GM was giving on Oldsmobiles, well see what happens. I had to get the transfer case replaced in my truck a few years back. So far it is ok.