Do you have iVA by ATS ? The price of this device is outrageous. But it can help 100% pinpoint the exact problem with bearings in differentials,center differentials, transfer cases and out of balance driveshaft and prop-shafts/u-joint problems, prop-shaft bearing problems. It's really important on newer luxury cars. I mean the 4Matic, Quattro and xDrive system. Most of these assemblies are serviceable. They have bearing , bushing and seals kit. But one needs to be sure which of the components is the culprit before taking it out of the vehicle and then servicing it. I've had a colleague replace the rear diff of BMW X5, but the real culprit was the transfer case. But THE BIGGER problem was that the junkyard rear diff was also vibrating , so after replacing the number one culprit - the transfer case , he needed to reinstall the old rear diff. It was quite a work! But he doesn't have iVA from ATS.
Yes, I am aware of that kit and the pico NVH kit. Both as you said are outrageously priced. With these Microphone clamps and the scope it will give you 100% accurate noise detection results at a fraction of the price. Vibration is a whole nother story. That's a crazy situation your colleague had
You are definitely correct on simply taking that approach. My main thing for putting this out was to show people that the ability to capture noise visually on a scope is possible and to try and inspire one's imagination of what else they can test with this method. To open people's minds and train of thought. Plus, the added bonus of using a scope is the ability of simultaneous measurement, meaning multiple noises captured at one time, one test. Not having to individually check each wheel (or whatever else you are testing) or unlike the chassis ear headphone unit, you have to hope you are on the correct channel the very moment a noise occurs and not miss it. With this, you set up as many chassis ears you need and start recording with the scope and drive not worrying about picking a certain channel. Hope this makes a little more sense as to why I made a quicky displaying this method.
