I've been trying to figure out how to use an external mic with a gopro, especially a directional mic with a windscreen. I think that would help maybe narrow down where in the rear axle the sound is loudest. But, I'm not seeing any ports in the GoPro to plug one in.YLG80 wrote: ↑Thu Apr 29, 2021 1:50 amIt's loud and clear that it comes from the rear side. Not from the wheels to me ...
The sound is very clear at the very beginning of each video, when you just start moving the jeep.
Now you should use an external microphone and stick it on some places like the rear transmission housing.
Nothing rattling with the muffler. I checked to be sure!
I've now mounted the GoPro near the muffler, you can't hear the clackity sound at all around it. Plus, I myself and two other people have 'leaned' out the Jeep to the point of almost falling out trying to figure out the sound. We're in agreement that it's in the rear, and you can hear it just as loud on the left as the right. If It was the muffler, you'd hear it clearly on the right. Plus, the sound is something spinning that's slowing down and speeding up with the rolling motion. Because it vanishes when in neutral (even if I hit the gas in neutral while rolling down hill, nothing).
It was pretty secure when I was rebuilding it. Plus, the sound is for sure coming from the rear axle.
That was my bad. The sound came after I put the drums on the second GPW axle. My adjustments for the brakes were not the best since I was in a rush at that point and just wanted to get them on for a test. So I only did a minor adjustment. Since then, I've had the drums resurfaced and I did a major adjustment. Squeak is all gone now!
That's actually one of things my Jeep expert friends have turned to saying it has to be clutch-related at this point since there's nothing left to check. But, there's a few issues with that...bazza46 wrote: ↑Thu Apr 29, 2021 2:41 pmHere's another lead you could consider. Could it be emanating from the clutch? Those 'Auburn style clutches have been known to 'clack' from looseness between the pressure plat and the bracket that holds it. Take off the floor plate and see if the noise is coming from that direction.
1) The sound is for sure coming from the rear axle.
2) With the floor plate cover for the transmission removed (and even the bell housing maintenance plate removed), the sound is not any louder. Seeing as I have a canvas top on the Jeep, it should amplify the sound if it was in the bell housing. This was something I tested when I rebuilt my transmission and transfer case thinking that was the source of the sound originally. I left the plates off so I could hear things better.
I'm not sure what a 1/2 shaft is? The sound does go away if I remove the rear driveshaft.
I might be doing that soon. I think we're getting closer to the sound with the GoPro videos (see next post), and trying to determine where in the rear axle it's coming from is the next step. I hope to do more GoPro videos such as in each wheel well (isolated from the differential housing) so it's just picking up the wheel noise on each side. Then as close to the Diff as I can get it (might even mount it to the rear axle in a few spots). But that's something I might end up having to do with a stethoscope. I think Harbor Freight even sells them for auto purposes.
Thanks for the charts! I've exhausted the driveshaft checking at this point. I've replaced the driveshaft with a totally different one. Both the yoke on the rear axle and the companion flange on the tranny are new (and the sound was there for the old ones as well). The U joint on the drive shaft (axle side) has been replaced with new u bolts. I've always made sure to use the TM manual when installing the driveshafts, making sure the yoke/flange are in phase with each other each time. The companion flange is nice and level. Now, when the axle dips forward due to me letting off the gas, it does dip downward on the yoke side, but that's a normal Jeep/axle function and I don't see anything out of the ordinary with that. That being said, I do feel that the downward deacceleration motion of the rear axle IS what is causing the sound. WHAT is making the sound from that motion is the mystery.W. Winget wrote: ↑Fri Apr 30, 2021 6:09 amFor my two cents, no one asked about phase of u-joints. If they are out of sync it will make noise, usually happens as someone didn't align the spline arrows on the yoke to drive shaft, or check the axle input flange angle to transfer output angle (which moves if the axle twists or springs are worn).
As far as the engine valves go, I did actually change the head of the block (it was post-war) to a GPW one after about 300 miles on the Jeep with the noisy valves. No abnormal marks on the top of the pistons that would make me think it's striking nor any abnormal marks on the bottom of the head. I do have one of the nice copper gaskets on there at the moment. It's one of those things where I'll eventually get to doing more in-depth work on them!
I've done that with old headphones in the past! Ha ha. I think Harbor Freight sells cheap stethoscopes for auto work! I might just go with that and the GoPro videos to try and hone in on this issue.
This is the first I've heard of this. I had a Jeep expert friend come out and spend some time with my Jeep. His diagnosis was similar to that ('learn to ignore it, it's not a mechanical issue because there's no vibrations/jerkiness/etc feelings that correlate with the sound'). See more in the next post about that. But the issue here is two different axles have this issue, and with mine it's actually different as you can't hear the sound in neutral. You have to be in gear.Warren Duchesne wrote: ↑Fri Apr 30, 2021 6:23 pmI have heard many WW2 Jeeps that have a clacking sound coasting down from speed in neutral with clutch depressed. Clacking decreased as speed decreases.It has nothing to do with engine speed. The sound is related to vehicle speed and the speed of the clacking has to be related to the speed of the driveshafts. I have never searched for the noise because I don’t believe it’s a actual mechanical problem.