Hello, my name is John Kelly. And this is the Weber Auto YouTube channel today, I'm going to demonstrate how to use the new NVH app to diagnose a driveshaft speed, related vibration I have a vehicle set up with a vibration installed on it. And we are ready to go drive do a road test. So let's set the app up for the vehicle that we are going to use here. So if we start the app with an agree, the vehicle that I'm driving is an older vehicle that is not in our database of vehicles. But you can actually use. This app on any vehicle.
If long as you enter the vehicle information, that's required. So in this case, we will go with unlisted vehicle in the upper right-hand corner. This is a four-wheel-drive truck. So I'll click on four-wheel-drive. We have to enter the number of cylinders in the engine. This is a six-cylinder engine. We have to enter the rear axle gear ratio to find the rear axle gear ratio.
We have a link. The reads find my axle gear ratios, right there on the screen scroll down. This is a GMC. So.
We'll, select GMC, General, Motors vehicles have a code labeled somewhere in usually the glove box or the trunk area. And you will find a code that begins with the letter F or the letter G for trucks. It's the letter G. And this truck has a gu6 axle code. So scroll down to where you find gu6 and look in the next column. It gives us the axle gear ratio of three point, four two.
So we will hit done we'll come to the axle gear ratio box and punch in three point. Four two. It asks us for the transfer case gear, Ratio on this four-wheel-drive truck, if you're driving around in two-wheel drive or four-wheel drive high, which you normally wouldn't do on dry roads.
The transfer case gear ratio is just simply 1 all right. So the next thing that we need is the transmission gear, ratio. So we'll click on transmission. Gear, ratios. This is a four-speed transmission.
But notice we can hit the plus or minus buttons to select the number of speeds in the transmission. And this is a 4-speed so I selected 4. We can just go. With default gear ratios, if you don't know what your gear ratios are, but I do know what transmission this has and the way I find that out is to look at find my transmission. Gear, ratios, the link right there on the screen and scroll down to GMC and on the code label that I have on this truck, I have a m30. And so m30 right here is a 4l60 ii transmission. And if I scroll over there's, the gear, ratios, three point, five or three point, zero, five, nine.
One point, six, two, five one and zero point, six, nine. Six so I will come back here and punch you in three point, zero, five, whoop, three point, zero, five, nine. One point, six, two, five, one point zero and zero point, six, nine, six, the app needs to know, the transmission gear, ratios to calculate the rotational speeds of some parts on your truck. So the last thing you have to enter for whatever vehicle you want to test is the tire size. This truck has two 3575.
Fifteen tires on it. So now we hit start. It brings us to the vehicle view where we have a. Powertrain view of a four-wheel-drive vehicle. And now we're going to hit start recording and go drive it and see if we can pick up this vibration so let's, go ahead and let's see what we can find. Yeah, I'm going to sit the iPhone on the dash and cover it up with a piece of paper. So the Sun doesn't, overheat it and let's go see, or we can find they're showing up driveshaft.
First order click who got a third-order tire along with it. So here we are at 73. 74 miles an hour. We've got glowing driveshafts. Glowing tires looks like we have multiple vibrations on this vehicle looks like it's worse at the higher vehicle speeds. Our drive shaft speed is around 50, 50 revolutions per second all right I'm going to tell the app to stop recording. We can get off and go back I will give it a name.
2001, GMC, Sonoma with a d1 driveshaft, vibration hit save the app will analyze the data. It has recorded and tell us what it thinks it's found is the source of the vibration. Now, remember the app will give us the highest. Average amplitude frequency over the time that we drove, so it's telling us that we have a third order, tire speed related vibration as the primary cause of the shaking as we drive. And of course, you can click on.
How do we fix this vibration? It brings up a help file that tells you how to repair that let's go back and look at the totals. Notice we have.
Third order tire was detected 225 times during our road test. And a first order driveshaft was detected 156 times and let's see what speeds they were. Worse at on the third order tire, it looks like 70 to 74 miles an hour. It was detected 158 times all the other vehicle speeds were pretty minor let's. Look at the first order driveshaft. It was detected 109 times between 70 and 74 miles an hour.
And the rest of the time looks like 50 to 54 miles an hour. It was detected 14 times. So a lower speed at lower speeds that came in.
And again, at higher speeds. Engine vibrations, there were a few that were picked up second-order engine was the most second-order. Engine vibration on a v6 engine is one of those normal vibrations that we should not be feeling in the passenger compartment. So this little truck actually has three different vibrations. But the one with the highest average amplitude of 0.148 was the third-order tire, followed by first-order drive shaft as 0.169 now, that's a higher amplitude. But it was only detected 156 times versus the 225 times for the third order tire. So it's, not just amplitude it's, a weighted amplitude level based on.
How many times it was detected let's, look at our graph there's, a lot of blue there that blue is the driveshaft speed related vibration. This graph shows amplitude versus time, and the color represents the frequency of the part on the vehicle. Okay, well that is how to manually enter a vehicle's information. Once again, this app will work on any vehicle as long as you can come up with the gear ratios and tire size and number of in engine, cylinders. And so on it'll it'll work, all right now. The app gave us help for the third-order tire speed vibration. But if we go all the way back to the first menu here and look under the diagnostic help icon and then diagnostic procedures, it has a separate menu item as you can see here for tire speed, related vibrations.
And it breaks it down by the orders, driveshaft speed, related vibrations, and the particular orders' engine, speed vibrations and their orders. And each type of vibration has its own specific diagnostic procedures that all of those. Procedures are in these help file links while we're driving here if we click on, if we go back to the main menu and click on tools, there are several tools here, available, and we'll, take a look at these in different videos. But one of them is just simply a vehicle speed signal that would be based off of the GPS speed signal as we drive. So it says, we're doing 33 miles an hour, and that matches our speedometer, the GPS vehicle speed is actually more accurate than your speedometer, because your. Speedometer is based on the tire size that you have on your vehicle, and as your tires wear out, your speedometer becomes less less accurate. Now we have a live data tool where we can just look at the frequencies and the amplitudes that are being measured as we drive down the road.
So it will show you the top five frequencies as far as amplitude levels with that tool. We have a strobe light tool that will actually flash your camera's flash a certain number of times per second, and we'll use that tool. In another video for engine for abnormal engine vibrations.
And then we have another tool for measuring driveshaft u joint working angles and help for correcting those. This has been a demonstration of using the NVH app to detect drive line or driveshaft speed related vibrations. It turns out we picked up a few other unexpected vibrations on this old truck at the same time. Thanks for watching you.