symptoms of possible unit bearing/hub failure D30 front ?
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The short story is I have a rotational noise in my front end.
It disappears if I steer left, says the same right or straight ahead.
it is most prominent at 30-50mph, less so at higher speeds
Sounds to be coming from the "long side" of the diff (I am RHD), so DS
There is no appreciable vibrations. A physical exam reveals no apparent free play
My next easiest option is to replace the long side unit bearing with one from a dismantled D30 I have, and see if that makes any difference to the noise
What I have tried so far;
replace wheel & tyre, remove front driveshaft, check and slightly adjust alignment (at home), all no change
Alignment seems good, was almost parallel with both straight edge and measuring with tape measure, I adjusted so there is about 1/32" toe in
The long story, originally replaced my transfer case as it was making a frightful noise from the rear, then I could hear this (much lesser noise), so started hunting
During this hunt, I found the following parts needed replacing, front springs (bent) DS upper ball joint with .005" OS (flogged out), LCA bushes (Chinese poly)
I have reset my LCA so front driveshaft and pinion angle are within 1 degree
All with no change in the sound, I think it is getting worse
The fact it disappears when I turn left is what makes me think it is in the unit bearing
I dont think its the uni-joint, and swapping the long side one is to be avoided, as it can easily make the inner seal leak oil
Anyone replaced a unit bearing and if so did it make a varying noise when bearing either side ?
It disappears if I steer left, says the same right or straight ahead.
it is most prominent at 30-50mph, less so at higher speeds
Sounds to be coming from the "long side" of the diff (I am RHD), so DS
There is no appreciable vibrations. A physical exam reveals no apparent free play
My next easiest option is to replace the long side unit bearing with one from a dismantled D30 I have, and see if that makes any difference to the noise
What I have tried so far;
replace wheel & tyre, remove front driveshaft, check and slightly adjust alignment (at home), all no change
Alignment seems good, was almost parallel with both straight edge and measuring with tape measure, I adjusted so there is about 1/32" toe in
The long story, originally replaced my transfer case as it was making a frightful noise from the rear, then I could hear this (much lesser noise), so started hunting
During this hunt, I found the following parts needed replacing, front springs (bent) DS upper ball joint with .005" OS (flogged out), LCA bushes (Chinese poly)
I have reset my LCA so front driveshaft and pinion angle are within 1 degree
All with no change in the sound, I think it is getting worse
The fact it disappears when I turn left is what makes me think it is in the unit bearing
I dont think its the uni-joint, and swapping the long side one is to be avoided, as it can easily make the inner seal leak oil
Anyone replaced a unit bearing and if so did it make a varying noise when bearing either side ?
Last edited by awg; 07-29-2024 at 10:10 AM.
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Not sure what you mean by "unit bearing" but a bad wheel hub bearing will definitely give you the noise when turning symptoms you describe and the bearing doesn't need to be loose enough that you can feel slop.
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Unit bearing is technically more accurate. Changing when swerving is a telltale sign it's a wheel bearing, although I've had a bad one that didn't change when swerving. I also had one that tricked me into doing the wrong side by getting quieter when loaded on the outside of a turn. I've also almost replaced one before realizing it was the dust shield rubbing.
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Thanks for the suggestions
Yes, I am going to just pull apart the DS, which is my main suspect, measure and inspect everything, use the spare I have, and it should either fix it or change it..if its the problem
I do have another spare, so I could then do the other side
not a big job, something should change
"Unit Bearing" is the correct description, check FSM, Parts Manual or Rock Auto. It consists of the wheel bearing and wheel hub built into one integrated unit
I am wanting it to not be in the pumpkin, and the quiet on left turn gives me hope. I will pull the cover and do an inspection if this doesnt work
It seemed to be grinding a bit on the DS wheel area when I was braking today, so that is indicative of DS
The "good" thing about "noise issue" diagnostics, is "they get worse"...thats what I tell others anyway lol
I stop and assist every motorist that looks like they need it, unless I am time constrained.
Today, I rescued a beautiful woman, out of her area, broken down over heated in a bad spot
I had 10L of water, filled it up, got the engine started, checked no leaks, assured her a service station was 5min down the hill (hope she doesnt have a blown head gasket)
The lady who I was chauffeuring was impressed as well, so it was a good feeling all-round
Yes, I am going to just pull apart the DS, which is my main suspect, measure and inspect everything, use the spare I have, and it should either fix it or change it..if its the problem
I do have another spare, so I could then do the other side
not a big job, something should change
"Unit Bearing" is the correct description, check FSM, Parts Manual or Rock Auto. It consists of the wheel bearing and wheel hub built into one integrated unit
I am wanting it to not be in the pumpkin, and the quiet on left turn gives me hope. I will pull the cover and do an inspection if this doesnt work
It seemed to be grinding a bit on the DS wheel area when I was braking today, so that is indicative of DS
The "good" thing about "noise issue" diagnostics, is "they get worse"...thats what I tell others anyway lol
I stop and assist every motorist that looks like they need it, unless I am time constrained.
Today, I rescued a beautiful woman, out of her area, broken down over heated in a bad spot
I had 10L of water, filled it up, got the engine started, checked no leaks, assured her a service station was 5min down the hill (hope she doesnt have a blown head gasket)
The lady who I was chauffeuring was impressed as well, so it was a good feeling all-round
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Last edited by awg; 07-30-2024 at 10:24 AM.
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