On Car Propeller Shaft (Driveshaft) Runout Measurements

On Car Propeller Shaft (Driveshaft) Runout Measurements


okay this is a demonstration of propeller shaft run-out measurement and since I’m alone here doing this video I don’t have someone else to help me turn the propeller shafts so what I’ve done is started the engine on this truck put the transmission in low in first gear and put the transfer case in low and that way the rear propeller shaft here is rotating about one and a half times a second which is the slowest speed I can get it to but it’s slow enough that we can hook a dial indicator up and get some run-out measurements so this is a two piece propeller shaft as you can see right here this first piece at the back of the truck is aluminum and it goes up to a center support bearing right up there where it changes to a steel drive shaft propeller shaft and then it goes up to the back of the transfer case and we are going to measure run out in several several locations on both the the steel propeller shaft and the aluminum propeller shaft I’m going to start in the front on the steel propeller shaft and you might be able to see it here right there I actually have the dial indicator with the roller tip hooked up so we’re gonna go up there and take a look at what run out we get okay here we are at the back of the front piece of the 2-piece propeller shaft on this 2007 tundra we’ve got the center support bearing right there and our Center u-joint and then going up to the front we’ve got the transfer case that it hooks to at the front but I’m going to start right here in this middle area on the steel propeller shaft and I’ve got a dial indicator hooked up as you can see and I’ve got the roller tip plunger or riding against the propeller shaft and of course be careful with the rotating propeller shaft if you do it like this by yourself that you don’t get wrapped up in it I know all of you are used to working around rotating and moving moving equipment but this is just a precaution so if we zoom in and look at this dial indicator get it focused here there we go we’re toggling between zero and five ten fifteen looks like between zero and about thirteen fourteen thousandths of an inch so the maximum run out on this vehicle in the service information is more than that but it’s quite a it’s quite a thing to see see that plunger moving up and down with the propeller shaft rotating because it’s we assume that these things are round but they have out of round problems they have run out problems and if the run-out is excessive it can lead to a first-order propeller shaft speed related vibration so next we’re going to move this dial indicator to the front of this steel propeller shaft and see what it has to run out okay here we are at the center of the front steel propeller shaft and I’m going to check the run out here same way so let’s see if we have I can get it to focus come on focus there we go okay it’s toggling between about zero and 25 thousandths of an inch we’re pretty close to them the maximum allowed here in the middle and you’ve got to check the middle besides the ends of the propeller shaft because it could in anywhere as excessive run-out could lead to this first order propeller sheet propeller shaft speed related vibration so think of this propeller shaft is having a more run out in the middle than it does on the ends okay here we are at the rear piece of the propeller shaft on this 2007 tundra this is our rear u-joint the number three u joint and we’re looking at the back of the aluminum propeller shaft and got the dial indicator on you know let’s zoom in and see what we get it’s like we’re toggling between about zero and thirty five thousandths of an inch I believe that is more than we’re supposed to have but that does not mean that it will cause a vibration but if you have a first-order propeller shaft speed related vibration and you have excessive run-out you need to fix the run-out now the extra shaking that I have here is because I have the magnetic mount for the dial indicator actually hooked to the exhaust system and so we’re gonna have a little bit of shaking from the engine but that will not affect the overall maximum and minimum that the that we’re looking at as a pattern here and we’re right around 35 thousandths of an inch so now we’re going to move to the middle and see what we get there on this aluminum propeller shaft okay we are at the middle of the aluminum propeller shaft I’ve got the dial indicator hooked up with the roller tip and if we look it’s a little darker here but it it’s toggling between zero and about 35 thousandths of an inch which I believe is too much for this vehicle now we’re going to move one last measurement to the front of this aluminum propeller shaft okay here we are at the front of the aluminum propeller shaft measuring run-out the dial indicator and as we zoom in here it looks like we’re toggling between about 1 or I’m sorry between zero and 20 so 0 to 20 thousands of an inch that’s well within specifications so that portion is good so we’ve got six different readings on this rear propeller shaft for run out and check your service manual for maximum ran out specifications but if you have anything that’s more than the maximum then you need to replace the the propeller shaft or have it repaired to correct the run-out and you need to do this before even thinking about trying to have it balanced this has been a demonstration of measuring propeller shaft run-out on the vehicle


Leave a Reply

Your email address will not be published. Required fields are marked *