B1G_xyz Posted March 30, 2023 Share Posted March 30, 2023 Im hearing a humming noise that gets faster/louder as I accelerate. Not sure if you can hear it on the video, but I've checked the wheel bearing, tire and wheel are good, and also checked my brakes. It sounds like it's coming from the driver side rear. Any tips would be appreciated. 20230319_152808.mp4 Link to comment Share on other sites More sharing options...
KZJonny Posted March 30, 2023 Share Posted March 30, 2023 Not taking a stab at you here, but how did you ‘check’ the bearing? I ask honestly because I’ve had humming in my bearings, and even tho they had no play I could find/see, and using my stethoscope they didn’t really make any grinding or terrible noise, replacing them stopped the humming. + the old units coming out were not as smooth turning as the new ones. Guess it doesn’t take much damage to the tolerances in a wheel bearing to start making noise. They’re a known bad part of these cars… Hard to say from the video audio quality, but it doesn’t sound like the diff anyhow… Link to comment Share on other sites More sharing options...
B1G_xyz Posted March 30, 2023 Author Share Posted March 30, 2023 10 minutes ago, KZJonny said: Not taking a stab at you here, but how did you ‘check’ the bearing? I ask honestly because I’ve had humming in my bearings, and even tho they had no play I could find/see, and using my stethoscope they didn’t really make any grinding or terrible noise, replacing them stopped the humming. + the old units coming out were not as smooth turning as the new ones. Guess it doesn’t take much damage to the tolerances in a wheel bearing to start making noise. They’re a known bad part of these cars… Hard to say from the video audio quality, but it doesn’t sound like the diff anyhow… I did the old test of lifting the car up and shaking side to side and up and down for play, but it's solid. I swapped all 4 bearing about 2 years ago with timkens also. But from what you're saying it can still be the bearings? Link to comment Share on other sites More sharing options...
KZJonny Posted March 30, 2023 Share Posted March 30, 2023 I doubt 2 year old timkens have gone bad, so probably not. It was more that the bearings in these cars aren’t awesome, particularly if you have a wagon and like to haul stuff. If you’ve got enough play in your wheel you can feel it with the ‘wheel shake’ test, and the cause is a bearing, it’s waaaaaay past due to replace and probably shouldn’t have been on the road. The amount of damage/out of spec for sealed roller bearings in a wheel would be like… thousandths of an inch. You might feel it as a roughness in the bearing or a grinding noise if it’s compromised. A wheel that moves around because of a bad bearing would be no bueno. 1 Link to comment Share on other sites More sharing options...
B1G_xyz Posted March 30, 2023 Author Share Posted March 30, 2023 2 minutes ago, KZJonny said: I doubt 2 year old timkens have gone bad, so probably not. It was more that the bearings in these cars aren’t awesome, particularly if you have a wagon and like to haul stuff. If you’ve got enough play in your wheel you can feel it with the ‘wheel shake’ test, and the cause is a bearing, it’s waaaaaay past due to replace and probably shouldn’t have been on the road. The amount of damage/out of spec for sealed roller bearings in a wheel would be like… thousandths of an inch. You might feel it as a roughness in the bearing or a grinding noise if it’s compromised. A wheel that moves around because of a bad bearing would be no bueno. Ok I'll keep that in mind, thanks 1 Link to comment Share on other sites More sharing options...
m sprank Posted March 31, 2023 Share Posted March 31, 2023 If the bearing wobbles it has been bad for some time. That is not a test. If you can hear it, it is failing. If it is a rotational noise isolated to a specific corner a bearing would be first suspect. There are tools to help troubleshoot, but none to "test" a bearing. In my experience OEM are best. 1 Link to comment Share on other sites More sharing options...
silverton Posted March 31, 2023 Share Posted March 31, 2023 wheel bearings can feel tight while still making noise 1 Link to comment Share on other sites More sharing options...
m sprank Posted March 31, 2023 Share Posted March 31, 2023 5 minutes ago, silverton said: wheel bearings can feel tight while still making noise Oh the sarcastic comments that come to mind. What else still feels tight but makes noise??? 1 Link to comment Share on other sites More sharing options...
B1G_xyz Posted March 31, 2023 Author Share Posted March 31, 2023 6 hours ago, m sprank said: If the bearing wobbles it has been bad for some time. That is not a test. If you can hear it, it is failing. If it is a rotational noise isolated to a specific corner a bearing would be first suspect. There are tools to help troubleshoot, but none to "test" a bearing. In my experience OEM are best. I understand that, but before I go and replace it what tools are there to troubleshoot further? I'd hate to replace a good bearing if that's not the issue. Link to comment Share on other sites More sharing options...
KZJonny Posted March 31, 2023 Share Posted March 31, 2023 No tools that are cheaper than a new bearing, really. At least ones that will tell you something meaningful. Do you have a decent quality FLIR camera? Like not one that attaches to a cell phone... You could probably see a heat differerence between sides if you went for a spirited drive, and got out to look right away, but that's just spitballing. There is almost certainly some kind of rotational torque measurement tool that would fall into the correct range to attempt to spin the wheel in it's unloaded state and give you a value, etc.... Probably be $1k+++ and who knows what the good/bad value is? Ultra cheap method would be a mechanics stethoscope and having a listen to one bearing vs. the other(s), but I didn't have a lot of luck with that personally. You may have better luck that I did, however. Maybe the FSM has something to say about it. Don't have that on this computer, so I can't say what Subaru recommends. Probably involves a very expensive special tool... Link to comment Share on other sites More sharing options...
KZJonny Posted March 31, 2023 Share Posted March 31, 2023 Just wondered if you've had a good look at the e-brakes by chance? Could be something rubbing inside the rotor hat? Around here, rust will sometimes cause enough expansion/flaking of the dust sheild/backing plate to cause actual brake noises and problems. It's a longshot, but sometimes when people say "checked my brakes" they just looked at the calipers/pins etc..... 1 Link to comment Share on other sites More sharing options...
B1G_xyz Posted March 31, 2023 Author Share Posted March 31, 2023 I actually did! The dust shield actually did have a lot of rust, so I took everything apart and used a wire brush to clean the inside of the rotor. Probably should've mentioned that along with all 4 brakes having new rotors and pads as well. Was really hoping that was the cause lol Link to comment Share on other sites More sharing options...
silverton Posted March 31, 2023 Share Posted March 31, 2023 (edited) I use a mechanics stethoscope if it's not obvious. while the wheel is spinning 35-40mph there should be silence while touching the probe to any of the 4 wheel bearing bolts, also the same test can be performed with your hand on a coil of the spring. you should be able to feel no vibration of any kind; if the bearing is good of course. Edited March 31, 2023 by silverton 1 Link to comment Share on other sites More sharing options...
m sprank Posted April 1, 2023 Share Posted April 1, 2023 Stethoscope if you can safely perform the procedure. Wireless microphone if you have the coin. Mic set up is far more than a few bearings. Stethoscope is cheap, but far easier with an assistant and a 2 post lift. Dyno rollers were to loud to troubleshoot wheel bearings, gernerally. Link to comment Share on other sites More sharing options...
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