Hello, my name is John Kelly and this is the WeberAuto YouTube Channel. In this episode we will be using the Pico auto NVH diagnostic kit, the Pico scope people, and this nbh diagnostic kit allows you to not only determine the source of a vibration on an automobile, but with an optional accessory you can balance a driveshaft in the vehicle of a truck or SUV or car. And it's an amazing setup. So I'm going to demonstrate how to do that with this. This tool set up today. Now this kit right here comes with an interface box because it has to connect to Pico with Scylla scope box. It has the accelerometer over here it's a magnetic tip accelerometer that hooks to the box it has a microphone that can be used in place of the accelerometer and as a couple of cables at the top here to help all of this connect to the Pico Scylla scope box itself. So if you buy this kit all by itself, that's that's not enough. This has to be used with a Pico oscilloscope and there are several different models that will work with it but the majority of them are 4000 series of oscilloscopes.
So either a two-channel or a four channel 4000 series oscilloscope there's a few three channel I'm sorry 3000 series that will also work you'll have to check the Pico website this particular scope is a 4423 oscilloscope scope and I'll open that up and show you this particular one it's just a blue plastic box we've got four inputs we have a USB cable to connect the oscilloscope box to the laptop computer so you need a laptop computer also this oscilloscope when we connect up the accelerometer it'll connect to channel B here and when we connect up an optional optical interface for measuring the propeller shaft speed and location we connect it to channel a so Oh by the way, this this rubber case here if you go to Picoauto.com they're selling rubber cases now to protect your investment in a in a Pico scope box. for automotive use if you're happen to drop it, it's gonna have better chances surviving in one of these rubber cases and they come in black.
Okay, so to balance a propeller shaft on a vehicle you need the Pico Scylla scope that I just showed you the Pico NVH diagnostic kit in the black box that I showed you. And then you also need an optional optical interface an optical sensor to connect to the to the door or to measure the drive line speed. So there that kit comes with this optical sensor interface and a cable that goes up to the interface itself or up to the optical sensor and here on this. This vehicle I've got the optical sensor installed. So this is the optical sensor right here when we plug in the sensor to the box and by the way that interface box has four triple-A batteries in it and they do go dead after a while the the sensor will flash or shine a red light you can see that red light that is shining up onto the propeller shaft and there's a green LED at the bottom of the sensor here.
Now you'll notice on the propeller shaft This is an aluminum propeller shaft and the entire surface is reflective and the way this optical sensor works is it needs to have a light flat its own light reflected back to it to measure the rotation speed of the propeller shaft and so I put some dark tape around the propeller shaft just some electrical tape. And notice if I turn the propeller shaft around we've attached a piece of reflective tape right there, you can see the light shining on it. And you can also see right here at the bottom of the sensor, that when that sensor picks up that reflective tape, it flashes the light now that light should come on right there where I've got it positioned with the reflective tape, but if it doesn't come on, then we have to reposition with the the magnetic attachment that that comes with the sensor, reposition the the sensor There we go.
So now the light is on all the time, I can interrupt it with my hand on and off there. Almost got the cord right in the way there. But we've got that light that turns on and off you want to make sure you've got a good setup, good adjustment there to where that sensor is picking up its own reflected light. Now notice that there It also comes with not just that optical sensor but it comes with this magnetic base that's adjustable you can attach it just about anywhere magnetic under the vehicle to get this sensor positioned where you need it to be. Okay, so for propeller shaft balancing the and the propeller shaft another name for propeller shaft is the drive shaft but most manufacturers don't call this the propeller shaft they call it arm sorry, they don't call it a driveshaft they call it a propeller shaft. So in this video, we will use those terms interchangeably.
Now what I have done on this particular propeller shaft is I've added some weight to it to cause it to be out of balance. So right here, I've added a hose clamp, this hose clamp ends up weighing just about half an ounce. And so that is going to throw off the balance of the propeller shaft here and cause what is known as a first order propeller shaft speed related vibration. And what first order means is it will create one shake per revolution. And by this time, you should you should never attempt to balance a propeller shaft unless you've eliminated run out. And you eliminate run out by putting a dial indicator on the propeller shaft in certain locations and rotating it and seeing does it turn perfectly or does it kind of wobble back and forth as it rotates.
And I have a separate video on YouTube on how to measure propeller shaft run out. So we've eliminated run out run out is not the problem on this vehicle. I've just added some extra weight here. But let's pretend that I haven't added the weight it's just out for some reason it's out of balance. And by the way, anything out of balance will only create one shake per revolution. So now we are going to use that kit that I showed you, along with some computer software to balance the propeller shaft. So if we go to Pico otto.com on the internet, we can download a piece of software called Pico diagnostics, you download it for free.
So that just started the Pico diagnostic software. And when it starts down here in the corner, the left hand corner it'll tell you if it's detected the Pico scope that we've got plugged in with the USB port. So we've got the Pico scope 4423 open successfully. That's what we want to see. And then off to the side here we have five buttons to select from, and the bottom one is NVH. That's noise, vibration and harshness. And I have a separate video on YouTube on how to use that feature to determine what the source of a vibration is on the vehicle. So for example on this vehicle we had we would have a vibration, we'd take it out on a road test, we would use the Pico NVH software to determine that it was a first order propeller shaft speed related vibration, and then come back, follow the help file that comes with the people's software or the vehicle service information for each vehicle service manufacturer and determine what to do to measure run out and balance the propeller shaft Well, that's the NVH button, the button we are going to use is balancing.
And these other three we won't even deal with today the compression test battery test cylinder balance. So today we are doing the balancing. So I'll click on balancing. And when we click on balancing, it gives us an option a couple of options. The top option here is called a pinion flange trial balance. And that is for those pinion flanges that they connect to a propeller shaft not through a universal joint the typical cross style universal joint that we're used to seeing in pickup trucks but with the flexible rubber coupling, as it's called a lot of passenger cars use that instead of a U joint.
On those, there are special balance weights that can be clipped on to the bolts that hold the flexible joint to the pinion flange. Well, we are not doing that on this vehicle because this vehicle uses a traditional universal joint zoom out here's so we can see it. So we've just got a standard cross style universal joint. And for that the software gives us a different option gives us an option that which is this bottom one have a hose clamp trial balance.
So we're going to go with that there are two options here we can go with advanced, which we will not do in this video, I will shoot a separate video on the advanced features of the Pico NVH in balancing software. But let's go with wizard the wizard is going to walk you through step by step and give you the instructions of how to set the vehicle up to balance a propeller shaft in the vehicle. So the first step, and then it's giving us here as you can, you can see is connect the Pico scope to a USB port, which I have done.
Already, we've got this blue cable connecting it to the laptop. So that's already connected. And notice in green text up here, it says it Pico scope detected or connected. It'll be red text, if it was not connected. So we will click Next. Now it tells us to connect the accelerometer to channel B of the Scylla scope. So I've got the oscilloscope right here. And channel B is right here. So here's our NVH interface box. For the accelerometer, I'm going to plug that in right there. And if we go back to the the screen it says tap the sensor to verify signal and it we've got this signal quality bar graph there. And so I'll I've got the sensor attached to the differential but let me take it down I'm just tapping on the the sensor itself and we get the the green bar graph going across the the screen so that's good. So now we will click Next to continue and it tells us to mount the accelerometer on the differential housing.
So where we are to mount this is about right here right behind the pinion flange right about the six o'clock position pointing up. magnet is very strong. Okay, we've got it pointing up at the six o'clock position out of the way of all these rotating parts. And so now we will click Next on the software. Now it tells us to connect the optical sensor to channel a of the oscilloscope. So back over here on the Scylla scope right here, I've got the optical sensor interface box. I've got it plugged in to channel a, right there. And then I've got the the sensor wire going up to the sensor itself that we've already looked at here on the vehicle.
Okay, so then the software, we're going to click Next, the software tells us to check the signal from the optical sensor. So let me zoom in so you can see the the screen here and it says Optos signal not detected. But if I come over to the sensor and enter, interrupt the, the, the reflection so I'm just cutting the beam with my hand, notice that it says optical signal detected in the green there. If you're not interrupting it, it's always going to show that it sensor signal is not detected. That's normal, so don't don't worry about that. So we will click Next. As long as it turns green when you interrupted it's good. So we will click next it tells us to mount the optical sensor base to a suitable surface and position the sensor with the lever focused on a half inch strip of reflective tape.
Well, the Opto optical sensor kit comes with reflective tape, you just chop off a little half inch strip and put it on the on the propeller shaft but like I said, if your propeller shaft is aluminum and reflective, anyway, you want to put something there to give it some contrast like black electrical tape. If it's a dark propeller shaft, you may not need to do that. But you may need to put some tape on there just to give the like some duct tape or masking tape to give it someplace to stick if you've got a real rusty or oily propeller shaft. Alright, let's click Next to continue. The next thing it wants us to do is enter this is attached to hose clamps around the shaft, mark the band at the end of the adjusting screw. Remove the clamps and cut the excess band at the mark. So let me zoom out and show you what we're talking about here.
So we are going to use two hose clamps, two hose clamps to balance the propeller shaft on this vehicle. And what we don't want to have happen is when you put the hose clamp on to have an excessive amount of this band coming up past this the screw because it can bend out. So you're going going to wrap it around the propeller shaft and put a little mark where the excessive amount should be cut off and then get a pair of tin snips and cut it off.
And notice that I've cut it off on a 45 degree angle on the tips there just a slight bevel so that we don't have a sharp edge to cut somebody. But that way when we put these hose clamps on the propeller shaft will tighten it up and there won't be any excess bands sticking out past the head of the screw. Another thing about these hose clamps these hose clamps weigh about and half a half an ounce, half of an ounce each. And if we were to take both hose clamps, and put them right next to each other like this, that will give us an equivalent weight of one ounce. But if we were to turn and mount them 180 degrees from each other, so totally opposite of each other like this, they counterbalance each other and the equivalent weight is zero. So we can go anywhere from a full ounce of weight to zero ounces of weight just by spreading these holes clamps apart and that's what this balancing software will do is it'll find the heavy spot determine how much these hose clamps weigh, which we have to measure them and enter that into the software and then it will tell you where to put these hose clamps and how far to spread them apart on the propeller shaft to give us a good balance on the vehicle.
So I've already cut these holes clamps to the right length so that we don't have any overlap on the propeller shaft. But here on the computer screen Besides telling us to
cut the, the bands to the right length, it wants us to enter, right here, the weight of the hose clip of the hose clamp. Now the hose clip is just the screw, head portion of the clamp. And so let me bring a digital scale over here. And you're probably going to need a digital scale because although the majority of hose clamp clips that I've measured are in the 14 gram range, which is the default value of the of the software. Not every hose clamp weighs 14 grams. So I have a digital scale here, I just bought it from a office supply store and you may have may have something already a post postal scale, but I'm going to set that right here. I'm a little tray, and I'm going to power this thing up. I've already taken a third hose clamp, so you're going to need a third hose clamp. And you need to cut off the head of the clamp.
So I cut off the clamp head right here, even with the the end of the screw. And I'm going to set that right here on this digital scale. Let me make sure it's on Yes it is. And we're going to set it when we turn it off, turn it back on. Alright, it's in grams, we can toggle between grams, and pounds. And so let me just set this head on there. And I'm currently getting 14 grams. So that's pretty typical of what you're going to see on hose clamps. But if you have a hose clamp that's larger or smaller, then don't just don't just assume that it's 14 grams.
Because if you don't enter the proper weight, it can throw off the balancing, it'll it'll tell you where to put the hose clamps to counterbalance the propeller shaft. And when you're all all done using the software, it didn't balance at the end of the balancing routine with the software, it doesn't show that it's that it's balanced like it should. So we have to make sure that you know what your hose clip weight is. We measure that again, 14 grams. Okay, so let's go back to the software, we are just about ready to actually start the balancing procedures. So back here on the software. The default value is 14 grams already got that entered. So I'm just going to click Next. The next thing it wants us to do is to measure the circumference. Let me zoom back in so you can see that measure the circumference of the propeller shaft. So the circumference is how far around the propeller shaft is.
So right up here, we are going to take a flexible tape measure and it needs to measure in millimeters. And we need to be as precise and as accurate as we can while we take these measurements because it affects the accuracy of the balance. And so what I've well the the the optical sensor that comes with the optical sensor kit, that's an option for the NVH diagnostic kit comes with a flexible tape measure and that flexible tape measure. I've used it probably a dozen times by now and it starts to get pretty worn with all the markings that we have to make on the propeller shaft. So I've looked for an alternate method and what I found is that on I like home repair places, Home Depot, Lowe's, whatever. You can buy a from sterrett, what they call a major stick. And it's a steel tape measure with an adhesive back as both inches and millimeters that it'll measure it measuring. And they're just a couple of bucks each and so I've I purchased those, they actually have a an adhesive back on it.
And just for an experiment, I decided one, I'm going to see if it'll just stick to this aluminum propeller shaft. And of course, the shaft needs to be really clean for the adhesive to stick. But when you put the tape measure on and measure all the way around, like I've done with this one, it started right here at the zero mark. Let me zoom in a little closer. So you can, you can see. So right here is the zero, Mark.
And we go around this direction, this is the direction of rotation, I put a little arrow off to the side here indicating that when this vehicle moves forward, the propeller shaft turns this way. So as we measure going all the way around, here's 10 millimeters 2030 4050. And as we continue around, here's 300 310. And this propeller shaft ended up being exactly 320 millimeters in circumference.
And so that is the number that we're going to enter into the software over here. So let me come over here, and we'll just punch in 320. And it'll auto, if we hit tab and tab down to the next box in the software, it automatically calculates when we punch in the circumference of 320, it automatically calculates the diameter of the pellet propeller shaft to be 102 millimeters. And then of course, the radius of a circle is half the diameter. So 51 millimeters would be the diameter 51 millimeters is also 5.1 centimeters.
And I'll I'll explain why you need why you may want to pay attention to that a little bit later when we're balancing the propeller shaft I think it'll help make sense of what we're doing in a few steps. Okay, so we've entered the diameter of the propeller shaft. And I would not recommend sticking at this flexible tape measure to a propeller shaft with the intent of leaving it there for her after you're done. But I have before the video I have run it up to a really high speed, it did stay very well. And I think it would work just fine for your initial measurements. And there's a lot of markings that we're going to make on this propeller shaft and so you'll need a like a fine tip, Sharpie permanent marker to make some marks on this propeller shaft.
Shut it off, Laura. Okay, so in the software, let's, let's go with next tells us before you begin gives us some pre pre balancing warnings and I'll add a few extras. Also, before you begin this balancing procedure, ensure the vehicle is properly supported refer to vehicle service information to determine what properly supported means. Well here on this truck. We've got it up on the hoist as you can see the hoist arms there, but we've got it sitting on these tall jackstands these high horse jackstands and so and then we've let the horse down to where the full vehicle says way to the vehicle is sitting on the suspension and by doing that we put the propeller shaft and the suspension system in its normal position for driving down the road and you want to do that because we do not want the angle of the the working angle of the U joint the angle of the propeller shaft versus the pinion shaft causing two shakes per revolution, which it can do if the angles are incorrect and I have a separate video on YouTube of how to measure those angles and and correct those.
So we have to have the propeller shaft at its normal position so the suspension loaded on the vehicle. Alright, the next thing that the software tells us to do is to remove rocks and debris from the tires. So we have these tires are going to be spinning at a fairly high speed as we are running this vehicle on the hoist, any rocks and debris in there can go flying out and possibly hit you or somebody else or a vehicle and cause some damage. You do not need to have had a lot of people asked me You do not need to remove the tires and wheels.
When you're doing a propeller shaft balance, they rotate at a speed that is the axle gear ratio slower than the propeller shaft. Even if they were out of balance and shaking, it would not affect the balancing of the propeller shaft because it's a different frequency. Alright, the next thing it says ensure all the leads are clear of rotating components. So all of our accelerometer and optical sensor leads need to be out of the way so they don't get caught up in rotating parts. The next thing is disable anti lock brake system and traction control if equipped. If a lot of vehicles have a button to just turn off traction control, if you don't see that you may be able to pull the fuse or just with the key off, unplug the anti lock brake module, electrical connector and that'll disable the traction control.
Also turn off air conditioning and other accessories. One other word of caution, and that is that on vehicles that have a center differential transfer case, and I have a separate video on center differential transfer cases and how they operate. Those vehicles are typically all wheel drive vehicles. But I'm not talking about crossover SUVs. And I have a separate video on crossover SUVs. Also, in the differences in the powertrain, there, I'm talking about just a regular full size SUV or pickup truck that has an all wheel drive feature, a lot of those have a center differential transfer case that acts just like an open differential in a rear in a rear axle. And so what that would cause to happen, potentially, is if you did not lock it into four wheel drive on the transfer case itself, so our transfer cases up here, if you don't lock that into four wheel drive, then it will act like an open differential of a rear axle here. And you've all seen where one tire can spin on the other one pretty much sits there. Well, what can happen with the center differential is one propeller shaft can spin and the other one just sits there.
Typically, it's the rear propeller shaft that does the spinning and the front one just stay stopped. But the problem is, it's spinning twice as fast as it normally would. And that would cause if especially if you had a rear differential that had an open differential rather than a locking or limited slip differential, that would cause one of your tires to spend four times faster than it normally would.
So a speed of 35 miles an hour on the speedometer would cause the propeller shaft to spend twice as fast, which would cause the tire to spin twice as fast. So 35 times four is 140 miles an hour, that tire would be spinning. And that's that's a bad idea. So lock it in four wheel drive that way it would be spinning half as half as fast. And if you end up having to spin things that fast, then you want to remove the tire and wheel assemblies put the lug nuts back on to hold the brakes in place so that we don't run the danger of having tires come apart because they're speed rated. And most of them are not speed rated. Do the 140 miles an hour that you could easily exceed. Okay, well let's go back to the software here and see what's next. So if we click Next on the software, it tells us to select the shaft speed. So what we want to know is what speed is the propeller shaft rotating and causing the vibration and so tells us to run the engine with the transmission in high gear but not direct drive not one to one and note the RPM that can be held steady at highway speed, and then place the transmission in neutral and stop the engine.
And we can also edit manually, we can punch this number in manually if we were already know what speed that is. But let's let's do it. Go ahead and start it up and take it up to the the speed. So we've got a red, we've got some red, the red number zero there. But notice as we start to bring the propeller shaft up to the speed where it was vibrating, that the numbers will, we'll switch from red to green, it'll switch to green, when it determines that the the vibration is occurring.
So when it's green, like right there about 2500 rpm. I'm going to click Next. Okay. Okay, it tells us the propeller shaft wizard is complete, we will hit finish. And now it takes us to a new screen. Alright, at this screen, we are going to back it up here just a little bit. It's given us a warning tone, telling us that it's not detecting the optical sensor. Let me kill the sound. I don't want to hear that. There we go. throughout the rest of these are throughout the rest of the procedure here, it's going to tell us to make some marks at different locations around the propeller shaft using that flexible tape measure. And we know for sure that it's going to have us make at least three more marks.
And what I've determined after doing this procedure multiple times now is that I'm going to make all those marks at once rather than stop and make marks only when it tells me. So the let's go back to the screen just for a second, I guess I need to show you something else. So it shows us a graphic right here of the propeller shaft. And in this first step, it tells us to place the first clamp on the shaft and mark that position as zero and then placed the second clamp on the shaft at 160 millimeters from zero. Well, if you recall, this propeller shaft is 320 millimeters in circumference. So half of 320 is 160. So we are going to just simply make a mark at zero, which I've already done on the propeller shaft.
So let's take a look at that. Let's get zero background here. So we've got zero right here. And I am going to extend that mark out a little bit longer. And what I'd recommend is that you use some sort of a straight edge to extend that mark. And and to draw all of your marks. You want to be as precise and as accurate as you can.
And what I've done here is I've tried to make the zero Mark approximately centered with this u joint bearing cap. Y is just a personal preference. You don't have to do it there you can actually do it anywhere you want. It's just I think that's a great starting point. So I'm going to take a fine point permanent marker and try to stay parallel with the propeller shaft as best I can. And that is our zero mark. Okay. Now it tells us to make a mark at 160 millimeters and they mean 160 millimeters in the direction of rotation. So our direction of rotation is this way. And so we will start Zero right here and work our way around. So you're 1020 3040, here's 100 millimeters. And here's 1020 3040 5060 160 millimeters. And it should be no surprise it's dead center with this other you joint bearing cap, which is why I line it up with the bearing caps. I like a visual indicator that it's that it's there. Okay, so that's our 160.
So I'm just going to write 160. There. Now, it's also going to have us make two other marks. At, what we're going to do is take the circumference of the propeller shaft and divided in three. So if we take 320 millimeters, which is the, or the circumference of this propeller shaft, we divide that by three every 100. And, well, 600 107 millimeters, we are going to have to make another mark. So if we start back here at zero, and we come forward to 107 millimeters, here's 100, here's 110. Just going to come back three millimeters to 107 is going to now the software does not tell you to do this right now, but it's going to tell you to do it. It just seems easier to me 107.
To do it right now, while I'm already making marks and have the tape measure out. Okay, then, since that's 1/3 of the way around the propeller shaft at 107, we need to go another 107. So 107 plus 107 is 214. So here's the 200 to 10 to 15 to 20. Let's go with the 214 right there, try to keep it as parallel as you can. So right there is 214. Okay, those are the three additional marks that you have to make on the propeller shaft. The software is going to make you do it anyway. So as I said, I like to do it. I've done enough of these now that I'm just going to do it all at once. So back to the the software screen here. It's telling us to put a hose or put one hose clamp at zero and the other one totally opposite of it at 160.
If you recall from our discussion, that means they counterbalance each other and that's like they're not there at all. But at least they'll be on the propeller shaft and ready to counterbalance. So let's go back to the propeller shaft. And let's go to the start at zero right here. Go into to take a hose clamp, put it around the propeller shaft and we're going to center that hose clamp. Right on zero. Got a little too tight. So I've made some alignment marks on the hose clamp itself also. So there is zero notice I made a just a reference mark on the hose clamp head so that I will always put that hose clamp head at the same same point. The software doesn't tell me to do that.
But I've done enough of these that it helps me to keep everything aligned. So right there, I'm going to tighten that up at the zero mark. We'll come back and we're still lined up. So now we'll come around to the 160 millimeter Mark halfway around. And we'll put the other hose clamp on and we'll center it on The 160 millimeter mark. Okay, and we don't want these right touching each other, just a little bit of gap. But here's our 160 meter reference mark on that hose clamp head to, it's nice and centered. Just be aware, when you tighten these hose clamps down, they tend to creep a little bit in the direction of rotation of the propeller shaft. But I'm still lined up. Also notice the direction of rotation is, is downward, we've got the screw of the clamp facing that direction, the head of the clamp facing the opposite direction.
Okay, so this is our first step. And on the software, they call that the initial run. So there is a, bring that in just a little bit a little bit closer here, this green button right here that says initial run, we're going to click on that. And then we're going to take it up to the 2500 or so RPM, propeller shaft RPM, where it was vibrating before and take a measurement now we have to do an initial run, and then three calibration runs. So the initial run is with the hose clamps opposite of each other.
Alright, go ahead and take it up. Okay. So I'm a software that there's a bar graph on the right, that red bar graph, we want it to be green, it needs to be in the green zone. And it's only a 100 RPM window that we have to deal with there. So it's, it's kind of hard to keep it centered, especially where I've got a helper up inside the cab that can't see this. We practiced and have it the speed approximately where we need it to be. But notice off to the left of that red bar graph is a completion graph. So once this is green long enough, this other graph will start to go up so they're came up just a little bit. Want to now come down just a little bit too low. There we go. We're in the green. As we stay there, notice the other graph starts to go up.
We want it to go all the way up to 100% as part of this initial run a little bit higher, almost there. There we go. So now Okay. So now it's it tells us the initial run is complete. Place transmission in neutral start the engine and notice on the instructions for the placement of the the hose clamps now, now it tells us to put both hose clamps right next to each other at the zero millimeter mark. Okay, so let's go up to the up to the propeller shaft. So here's the one already at the 160. So we're going to move that around to the zero mark right there. And then I'm going to tighten it up. So now we've got both clamps right at the zero mark. Okay, that looks good. I'm going if we go back to the software here. Now we are going to start our first of three calibration runs and each run will have us put both hose clamps right now.
Next to each other at three equally spaced locations around the propeller shaft. And that's why I made those marks in the first place. And as long as I calculated, right, you'll see here after we finished this calibration run, the the marks that it's telling us to put on are already there. So I'm going to go into click calibration, run one. Okay, take it up. Now we'll watch the bar graph.
On the right again. And what we're doing with these calibration runs is by putting both of these hose clamps next to each other, it's going to either accidentally make the overall vibration worse or better. And we'll try that in three different locations and determine which of those was the better location. And we can mathematically determine how much of a difference it made in each location, and then determine where the heavy spot is. And then it will tell us after our third calibration run, where to put the clamps to counterbalance the imbalance the hose clamp that I put on.
So we're just about done with our completion graph. There we go. Okay. Okay, so now notice it's telling us to put, if we look over here at the instructions, it's telling us to put the both clamps at 210 millimetres? Well, 210. Let's see, we had we made a mark at 214. So I don't know why it's saying 210. Because 210 is not 1/3 of the 320 millimeter propeller shaft circumference. So let's move these around. But it's only four millimeters off. But I'm going to put these at 214 rather than the 210. There's not a lot of difference there. But I understand what they're doing here. And I'm not sure why it told us to 10 Exactly. But let's see. Maybe 214 maybe I will actually I suspect I know why to 10 is the easy measurement to get with most flexible rulers.
Flexible tape measures to 14 might be a little more difficult to mark on a dependent on how precise your ruler is. So all right, I've got them both on 214. It tells us to tan but I don't believe it. I think 214 is where they really wanted it. And I'm going to click calibration run to on the software now. Oh, I forgot to show you on the propeller shaft. So I've got both hose clamps at the 214 millimeter mark, which like I said is just a tiny bit away from that to 10 where the software is telling us to put it Okay, so let's go back to our second calibration run on the software.
Okay, take it up again. Watch our bar graph. I'm signaling to my driver through text messaging. To go higher or lower. You can do that if you need somebody to help you or just put the laptop up in the driver's seat with you as you do it. This can be done on the floor with short jackstands and a creeper right on the line. Just a tiny bit lower. So close. Almost there Now to low it's a little frustrating, but that's just how it is. There we go. And we're done with elevation One, two, okay. Okay, so calibration run two is complete. Notice now it is telling us to put the hose clamps at 110 millimeters, where we calculated 107 would be a third of the way around. But I really do think it's just for ease of measurement that they're doing that. So let's go back up to our propeller shaft. And we're going to move both of these hose clamps to the well it says 110. But I'm going to I'm going to go to 107 because that's exactly a third of the way around.
We're only three millimeters off. So right there, tighten both of those down. So there we are. 107. Close enough to 110 we're only talking three millimeters. All right, now we're going to do our last calibration, run calibration run three. Okay, take it up again. And let's go back to the computer software. Hey, nice, good Green Zone there. That's perfect. Okay, almost done. There we go. Okay. All right. So we just finished our third calibration run. And now it tells us that we had an initial imbalance have 10 grams per centimeter. Now that the maximum allowed is 20 grams. It's not per centimeter, it's 20 grams per or 10. The maximum maximum spec. Alright, we'll get that out.
The it shows us that the initial imbalance is 10 gram centimeters. And that means that since we had a 5.1 centimeter radius from our discussion earlier in the video, and we have basically a two gram imbalance shown here on the on the software so a two gram imbalance here in the red at about 210 millimeters 211 millimeters that if ansara is messing up the we'll cut that out again, okay. It's it's showing us on the screen that our initial imbalance was 10 grams. centimeters, which meant that there was an imbalance of two grams. At about if you look at the screen closely enough here, about 211 millimeters, well, two grams, multiplied by the radius of the propeller shaft, which from our math earlier, we determined was 5.1 centimeters, two times 5.1 is roughly 10 gram centimeters, which is what we've got.
So it's telling us that we're out of balance by two grams at 211 millimeters. And we want to counterbalance that two grams at opposite of that on the propeller shaft with two more grams of weight, but the problem we have is that the hose clamps wave 14 grams each. So how do you make a 14 gram host clamp balance where two grams are needed? Well, you spread the clamps apart. And so what the software is doing is to tell is telling us to spread these clamps, we'll put our first clamp as it shows us here at 130 millimeters and the next one at 300 millimeters.
And that will spread them apart and give us an equivalent weight in between those two at about 51 millimeters would be the counterbalance spot equivalent weight of two grams. So remember when the hose clamps are totally opposite of each other at zero grams. As we start to move them closer together, we get one gram two gram and everything in between three, four or five all the way up to 14 grams each 28 grams when they're right next to each other.
So by spreading them apart, we counterbalance now just a point of interest here. Let's see if it detects if it detected where the host clamp that I added to cause this thing to go out of balance was that it's telling us the heavy spot is at about 211 millimeters to 11. So if we go up here to the propeller shaft, and it does not always work out, pointing right at the heavy spot of the where I put the hose clamp. The hose clamp I put is closer to 100 millimeters, it's telling us that about 200 here's 200 loan here's 210. Somewhere right here, this 211 right there is the heavy spot. So I'm just for grins, I'm going to put the letter H for the heavy spot and a little arrow pointing right there to about the 211 millimeter mark. And then we're going to spread the hose clamps out evenly. One of them will put at 10 or I'm sorry, one of them will put at 130 millimeters, the other one at 300.
So here's 210. So we'll come back to 130 which is right here for the one hose clamp, and let me make a little mark there. And we'll put the other one at 200. So there's 200 or no 300 at 300 millimeters, which is right here. So we'll put a mark right there at 300. And we'll extend that mark out because that's a second hose clamp that we need to to move.
Okay, so let's move these clamps. One of them at 130 millimeters and one of them at 300. So we're close to 300 here. So let's just move this hose clamp right here to 300 right there. Going to tighten that down. Make sure it stayed centered. Yes. Okay, then we'll move the other hose clamp to 130 millimeters which is right there. And we'll tighten that down. Make sure it's still centered. Yes. Okay, so now let's go back to the software. And this is what's called a verification run. So the green button off to the side there. I'm going to click with the mouse verification run. So we had an initial imbalance of 10, which is below the 20 maximum. So this isn't a very bad vibration that I've created. Let's see if we can make it any better by adding these, these clamps. Okay, take it up again. Okay, there we go. Okay. All right. And looking at the software, if you recall, we started with 10 gram centimeters of imbalance, notice that we did not improve it, we're at 10.4 gram centimeters, we're still below that the 20. But I want to make it, I want to make it a little bit better.
So to make it better, we need to counterbalance it with a little bit more weight. And so with my experimenting, what I found is that if you just move these hose clamps, just a tiny bit closer together in small increments, so here's our heavy spot, we're going to move this hose clamp up here a little bit closer to it, this hose clamp a little bit closer to it, we will just move it I'm just going to move at about 10 centimeters, which is about the width from the top of that screw right there to the mark that I made. Well, there's 300 that we're on the 90 is where we want to be lined up with so to the base of this clamp to that center there is about 10 millimeters. I'm just going to move that up a little bit, tighten it up. We'll come over here we will move this one down 10 millimeters bringing a little closer to the heavy spot. So by bringing these hose clamps closer, so we were at 130.
Now we're at approximately 140. So now we will tighten that up. And now if we go back to the software, it has an additional button on the right hand side here. It says free run and that lets us fine tune our balance. Okay, take it up again. And let's see if we can improve that any. Hey there we are in the green zone. Almost done. So close Come on almost there we go. Okay. So we actually made it worse by bringing it closer together. So we're, it's still below the 20. But we increased the imbalance by six, six and a half gram centimeters so that fine tuning was a little too much. So let's take it back and we'll bring it in just just not 10 millimeters we'll split the difference we'll go for five So remember, as long as it's below 20 supposedly that's fixed but the true tell is, is the vibration gone? Have you reduced the amplitude of the vibration and the initial imbalance is chauffeur's only 10 gram centimeters to begin with.
We have not reduced it mathematically according to the sensor here. But in in real life when you're doing this for a customer vehicle, I don't care what the number see if you've reduced the vibration how it feels while you're driving, then that's all the customer is really caring about. Alright, let's try this again. We're going to do free round again, we can do that as many times as we want. Okay, take it up again. Okay, getting closer. Okay. Ah, we still have an improved it we improved it a little bit from how bad we made it to begin with, but let's go back to where it told us to put them in the first place. For 15.8k, so I'm gonna line this right up again on the the 130 where it was and we'll put this one back to the 300 where it was they're tighten that down.
Okay, do it again. Okay, well we were not having much luck here we brought it down to 12 grams centimeters. And we started at 10.4. That is decreasing it. So against logic, I'm going to move those hose clamps just a little bit farther apart rather than closer together. That's what the fine tuning is all about here is going to move it a little bit farther apart. About five millimeters farther apart on each, each end. We'll click free run again. Let's try it again. Okay, take it up. Okay. All right, there we go. Finally. Okay. So this is this is not at all unusual, it is frustrating. But keep in mind, we were were balancing a propeller shaft that was only 10 grams centimeters out of balance in the first place, which is considered in in specification. Now if we look at our numbers, here, we are at we've we've cut it in half, we're down to 5.1 gram centimeters, which is excellent 4.1.
And I did that by spreading the clamps apart just a tiny bit from their initial 130 and the 300 millimeter marks. And that's just how this is you're not going to come in with this software. And whiz bang, boom, have it all done in after your three calibration runs in your verification. This is probably the two dozen time I've done this on a vehicle I've tried different vehicles every single time you have to fine tune it, either to get it to get below the 20 grams centimeters or to improve it like we did here. five grams centimeters is really good. I had a pickup truck on here on the hoist a couple of weeks ago and did it with our checked it just without any extra clamps added. And it was at 3.1 or three and a half, I think so 5.1 is pretty good. And we may be able to fine tune it and get it even closer. But I just wanted to show you that moving these clamps closer together or farther apart, gives us the ability to fine tune the software and it gives us or not finding the software to fine tune the balancing.
So this has been a demonstration of using the Pico diagnostic software with the balancing feature to balance a propeller shaft on a vehicle. And let's see the overall time it took us 43 minutes. That's pretty typical. And that does not include parking the vehicle on the hoist. So I I would imagine that I would quote someone at least one hours labor to do a balancing for the propeller shaft and we did a rear propeller shaft we could just easily do a front propeller shaft also. We did the rear of this propeller shaft just because it was close and convenient but we could have been Just as easily done the front, how do we know which one is worse the front or the rear of the propeller shaft? Well, the sensor itself using the NVH software rather than the balancing software will give us an amplitude reading of how harsh the vibration is. And we can have the sensor here at the axle.
We can have the sensor at the back of the transfer case or the transmission, see which one has the higher amplitude and that's the end of the propeller shaft that you should be trying to counterbalance. All right, well, this worked out great. Have a good day..
