Another noise thread. I'm stumped

biggy

biggy

Member
Im getting what seems to be a rhythmic noise from what feels like the front end somewhere .When it first started I would notice it when travelling between 50-60 mph. Now however I have noticed that it seems to be at any speed when I am in the 2800-3000 rpm range. Above or below those rpm's and the noise is not there. You can feel it in the gas pedal and the front driver and passenger floorboards. So just to be clear this is a rhythmic noise and also a vibration.

Things I have checked

1 Rotate tires front to back. ok
2 Removed front driveshaft and drove without ds ok
3 Inspect rear ds. Appear ok
4 Checked ball joints ok
5 Torque everything I can get a wrench on for suspension and steering components ok
6 Checked diff fluid level. ok
7 Inspect front shafts ok ( upgraded to 10 factory shafts last summer )

Could this be a vibration from the motor since it only happen at certain rpm's. I'm at a loss and any input is appreciated. Thanks
 
As you were describing this, the first two things that popped into my head was tires/heels or drive shaft. Sounds like the front is obviously not the problem, but a visual of the rear will tell you nothing. Sometimes they need balanced and visually look perfect. Any visual defects or scuffs? When you rotated the tires, did this change anything about the sound like location? Did u recently wheel or hit any potholes that could have caused any damage anywhere? The fact that it is rpm related sounds like something is out of balance to me.
 
StrizzyChris said:
As you were describing this, the first two things that popped into my head was tires/heels or drive shaft. Sounds like the front is obviously not the problem, but a visual of the rear will tell you nothing. Sometimes they need balanced and visually look perfect. Any visual defects or scuffs? When you rotated the tires, did this change anything about the sound like location? Did u recently wheel or hit any potholes that could have caused any damage anywhere? The fact that it is rpm related sounds like something is out of balance to me.
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Changing the location of the tires did not move the sound or feel. I will say this has been going on for a few weeks but seems to be getting worse as time goes on.
 
Have you checked your front unit bearing hub assembly for play? Mine did a weird wrrr, wrrr noise when it went out. Front axle nut was loose aswell. Didn't squeak at all, just rythmic wrrrrr'd at different times which I thought was weird too. I guess weight was being distributed more or less at different time under speed was my only conclusion since it didn't do it at all speeds and rpm's. Started off hardly noticable and got progressively worse over a couple months till I figured out what it was. Thought it was my tires at first.
 
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mkjeep said:
Have you checked your front unit bearing hub assembly for play? Mine did a weird wrrr, wrrr noise when it went out. Front axle nut was loose aswell. Didn't squeak at all, just rythmic wrrrrr'd at different times which I thought was weird too. I guess weight was being distributed more or less at different time under speed was my only conclusion since it didn't do it at all speeds and rpm's. Started off hardly noticable and got progressively worse over a couple months till I figured out what it was. Thought it was my tires at first.
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I didnt check that because it was only at certain rpm. I would think you would hear it at any rpm and speed if it was a bearing. Axle nuts tight because I pulled the shafts to do an inspection. You could be right though.
 
biggy said:
Would that not be felt at all speeds and rpm's
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In my experience no, it'll be heard/felt at different speeds. Check to see if your wheel hub has some play in it. Even if it has no play doesn't mean the bearings aren't failing. Jack up the jeep, take the wheel off and try hand spinning the hub to feel for roughness etc
 
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I pulled the front wheels off again and checked for play . I did check the ball joints already for excessive play and they were fine. This time grabbed the top and bottom of the tire and tried rocking the wheel. This time on the driver side I was getting about a 1/4" of play with no movement in the bj. Their is almost no play on the passenger side. I think Im going to change out the unit bearing and see what happens. Thanks for the advise and I will report back.
 
biggy said:
I pulled the front wheels off again and checked for play . I did check the ball joints already for excessive play and they were fine. This time grabbed the top and bottom of the tire and tried rocking the wheel. This time on the driver side I was getting about a 1/4" of play with no movement in the bj. Their is almost no play on the passenger side. I think Im going to change out the unit bearing and see what happens. Thanks for the advise and I will report back.
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Def sounds like a unit hearing. I had a driver side one go bad at 40k miles, and again at 74k. I replaced the pass side as well at 74k. Jeep drove great again.
 
highoctane said:
Def sounds like a unit hearing. I had a driver side one go bad at 40k miles, and again at 74k. I replaced the pass side as well at 74k. Jeep drove great again.
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The only thing that has me wondering is why the noise and vibe was only there between 2800-3000 rpm. Anyways I will change it and see what happens.
 
Well I changed out the unit bearing on the driver side and the vibe and noise are gone. Thanks everyone for your suggestions.
 
Good to hear!! Mine threw me for a loop aswell because it didn't do it all the time like a "normal" bearing would.
 
mo-jac said:
Cool! you made it easy to diagnose, "rhythmic noise" was the dead giveaway for me.
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Only bad part was changing it out in my freezing cold garage. I bought one for the passenger side as well but Ill wait for the warmer temps to change it out. Their is no play on that side right now. Thanks again.:thumb:
 
Sometimes that kind of noise will be heard only at certain speed. The vibration created at that speed generate a frequency that makes it audible of felt by the said vibration.
 
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