Humming noise while driving

[C-ya]

I am hearing a hum that changes pitch with speed changes. It is not a grinding hum, but more of a vibrating hum. Almost like resonance in a muffler. I am not sure where it is coming from. Both front hubs have been replaced. The transfer case loses fluid, but based on the last go round, it should still have some in it. The disconnect is clicking when on jack stands and in 4WD and the front wheels don't turn so I'm pretty sure it is gone. The driveshaft doesn't clunk when going from D to R or vice versa.

Any ideas on places to look?

Link to video of disconnect in case it is relevant: https://drive.google.com/open?id=1UJoO0pg-wRoq4HM26mlz3fAO-yWBkdMp Don't mind the camera looking everywhere and no where. I was trying to look and listen myself, so I wasn't terribly conscious of where the camera was pointing. The noise I'm hearing is not the clicking in this video, plus I'm not driving around in 4WD.

 

[Mooseman]

Don't discount the hubs as even newer ones can fail early, especially if of the cheaper variety.

 

[northcreek]

Are your roof rails moved to the back ?

 

[C-ya]

Don't discount the hubs as even newer ones can fail early, especially if of the cheaper variety.

I haven't, that's why I had it up on stands. Now that I have the brakes fixed (not dragging), I'll try that exercise again. Hopefully I can get the front axle to turn.

Are your roof rails moved to the back ?

No, but they have been in the same place for at least the last 2 years. I drive with the sunroof open in warm weather and I don't hear any noise. It was warm enough one day last week and I had the sunroof open but the noise has been going on for close to 3 weeks or so.

 

[Mounce]

Condition of tires? Check for choppy tread when you check the hubs.

 

[C-ya]

The tires are my summer / all seasons that I put on in June of '17. Because I use snow tires in the winter, they have 10, 600 miles on them. The tread looks good, flat, and even. The noise was happening with the snow tires before I swapped them out for the summers. That is why it was on jack stands for the tire swap.

 

[KEEBZ489]

i had a vibration / drone sounded like an exhaust leak but felt a vibration in the steering wheel to resonate with the sound. ive dealt with it a year now and had to change my driver side cv axle and bearing... noise is 50-75% gone.... hub was bad. next wek or two ill be doing the passenger side

 

[C-ya]

When I get some time and dry weather, I'm going to change the driver's side hub. I had my brother-in-law drive it by my house a couple of times and I listened from both sides and couldn't hear anything but I can sure hear it inside.

I'll get a disconnect on the way shortly and change that out so I can have 4WD again. Doesn't sound like the sound is coming from there, but I like 4WD in the winter when I'm pulling people out of their stuck situation.

Totally freaked the ABS system out when I had the truck on jack stands and the rears were turning but the fronts weren't. DIC says "SERVICE BRAKE SYSTEM!! OMGBBQLOL THE WORLD IS GOING TO END!!". Tech II showed historical codes for front left and front right wheel speed sensor but no current codes. Surprising, since it just happened and the message was in the DIC at that moment. Cleared them and it was good to go.

 

[gmcman]

Have you verified the front diff is full of fluid?

Does the pitch change when turning the steering wheel slightly to one side?

Generally when a front hub is going it sounds like a mud tire on the highway.

 

[C-ya]

@gmcman , I verified the front diff fluid level this past weekend, right at the fill port. I even checked the transfer case. It is leaking, so I'm watching it more closely. When I changed the fluid at 50K miles, only about an ounce or 2 came out. It was just below the hole, so OK atm.

The pitch doesn't really change much when turning, but it does change some. I'll have to go to a big parking lot and try big, semi-fast circles in each direction.

This does sound like a mud tire, somewhat. Not as loud, but definitely a droning sound. If you have had or heard a welded muffler drone, it is similar to that.


For anyone needing a disconnect, ebay has them for $158 with actuator at the moment. I also ordered a ball joint set. Right upper has some wear and moves in ways it shouldn't. Got that to look forward to, along with all four hub bearings in the wife's Kia Sportage. They are pressed in. Gonna try the hub tamer/grappler first before removing the entire unit from the vehicle. It does need an alignment since I replaced all four struts but I'm still going to try it to save some work hopefully.

 

[gmcman]

The fact only a few ounces came out of the transfer case is concerning. If you have a bearing issue in there, you could probably put the vehicle on jack stands and run it up to about 25-30 MPH and see if the noise is present. You won't need to load up the suspension to check for the transfer case noise so try that just to be sure.

I agree with Mooseman about the hubs, the fact it sounds like a low droning mud tire is a likely sign.

Do you have access to an infrared thermometer or a thermal imager?

I would drive it for about 5-10 miles, then check the heat of the hub behind the center cap next to the axle bolt at the hub face.

Another good location is behind the hub where the CV joint enters the rear of the hub.
This is where I viewed mine with a thermal imager and found one side warmer than the other.

My most recent set of bearings had about 13K miles on them and a tech at the dealer hit a curb on a test drive, I knew something was wrong because I thought the road was milled when I left. I found an abrasion on the side of the tire and I concluded someone there smacked a curb.....doesn't take much given the weight of these vehicles.

So if you think you or someone may have hit a curb or deep pothole recently, that could possibly be the cause.

Usually the Timken bearings or who ever uses the Timken...maybe MOOG....tend to have the better track record.

 

[TollKeeper]

Where do the ACDelco's come in on the chart of good/bad bearings? I have a option to get some AC's at a fairly reasonable price (much better than Timken or MOOG).

 

[mrrsm]

As mentioned in Post #2... courtesy @Mooseman ... One of our GMTN Members, Kevin Nadeau ... @Kevin nadeau made a very nice video of How to Diagnose the weird humming emanating from either one or both Front Wheel Hubs and perform the proper R&R Procedures that follow. @TollKeeper... ACDelco would be my choice for this R&R as well... But Kevin does mention an alternative choice of Vendors here, too:

 

[C-ya]

The fact only a few ounces came out of the transfer case is concerning. If you have a bearing issue in there, you could probably put the vehicle on jack stands and run it up to about 25-30 MPH and see if the noise is present. You won't need to load up the suspension to check for the transfer case noise so try that just to be sure.

I did this the other day when it was up on jack stands. There was no noise or vibration from the TC. The lack of fluid was discovered last year in July, about 5.5K miles ago. No noise until shortly after putting in a cheap hub bearing to diagnose the noise that ended up being a CV axle about 3K miles ago. I'm going to put the bearing back in that I took out. It is a replacement since I have owned the TB. No idea of the brand as a shop did it under aftermarket warranty. Both bearings have been replaced since I have owned it. This noise is not like the other two times when I had the bearings replaced. Those were both grinding type noises. This is more of a hum.

I agree with Mooseman about the hubs, the fact it sounds like a low droning mud tire is a likely sign.

Do you have access to an infrared thermometer or a thermal imager?

I would drive it for about 5-10 miles, then check the heat of the hub behind the center cap next to the axle bolt at the hub face.

Another good location is behind the hub where the CV joint enters the rear of the hub.
This is where I viewed mine with a thermal imager and found one side warmer than the other.

I also did this the other day when I put it up on stands. I have an IR temp gun. Both sides were right about 80 F, just above ambient that day.

My most recent set of bearings had about 13K miles on them and a tech at the dealer hit a curb on a test drive, I knew something was wrong because I thought the road was milled when I left. I found an abrasion on the side of the tire and I concluded someone there smacked a curb.....doesn't take much given the weight of these vehicles.

So if you think you or someone may have hit a curb or deep pothole recently, that could possibly be the cause.

Usually the Timken bearings or who ever uses the Timken...maybe MOOG....tend to have the better track record.

Interesting about the pothole/curb. Michigan roads in the winter leave A LOT to be desired in the smoothness factor.

Thanks for the thoughts, guys. When the weather gets decent - rain all week this week, and I get the time - hopefully an IDPA shoot this Saturday plus I need to do some work on my TLR, I'll try to get this front end sorted out. I would also like to wait until the disconnect and ball joints are here to try to knock it all out in one day.

 

[Mooseman]

Just a note on why nobody has used ACDelco hubs is because they were always so damned expensive, and are still the most expensive at RA for their Pro line, which actually have a lifetime warranty, which might make it a good option if keeping it for a very long time. Even the Timken only has 12 months and SKF 36 months (and is actually cheaper). Raybestos and Mevotech also have lifetime but I trust them like I trust Chinese brake pads.

 

[TollKeeper]

Well the ACDelcos I found have no warranty, but are 65, 50 if you buy 2, bucks. I run thru the wheel bearings about every 3-4 years. The ones in it now are Timkens, I installed them in 2015, and started grumbling about 2-3 months ago. So out of warranty, but something needs to be done now that its warmer.

eBay - ACDelco Hub Bearings

I replaced the wheel bearings in..
8/09 (first thing I did when I bought the truck for ABS kickback, factory OE bearings)
10/12
7/15
And doing it again this month

 

[Mooseman]

Looked at those closely and like anything else on fleabay, they could be Chinese fakes. The part number they have doesn't match anything and the closeup on the hub is unreadable and doesn't seem to match the last numbers. The F3Q005MX also doesn't match anything and only brings up eBay, Amazon and some Spanish sites.

They look dicey at best.

 

[TollKeeper]

The F3Q005MX is the part # used in the Mexico parts catalog..

That being said, after looking at them, I do see a bit of sketch. I know GM OE parts for hubs have that yellow lock tite on the lug threads, and these do not.

Im thinking about buying 1 ACDelco from my local parts store (lifetime warranty, $223 bucks) and see how it goes. Since I know I go thru them, it just makes sense, at least to me.

 

[mrrsm]

The ACDelco F3Q005MX Wheel Hubs that were offered for sale at one time on Amazon are now being shown as "out of stock"... and so it makes me wonder whether or not they obtained some of the counterfeit variety and later received complaints about the problem. These two attached images are meant for making a comparison as to how the OEM are supposed to look versus anything else that is being sold on Amazon as true ACDelco Wheel Hubs for the Trailblazers/Envoys:

 

[coolasice]

I've been rocking Detroit axle bearings since 2016 with no issues. I'm probably 12k to 15k mi on them. Cost me less than $100 for the pair. for that price and the time interval that it takes me to change them (2hs every 3yrs) I'll buy these any day.

 

[TollKeeper]

Linkies no workie?

 

[C-ya]

Driving around today getting rental tools for the jobs at hand, I guess I got enough miles to get some temp into the bearings. The right side was about 100F while the left side was about 80F. So my plan was to swap right side with the one I took out of the left side about 3k miles ago when T/S noise from that side when in reverse and turning (drive axle was the culprit). Just under 49K on a bearing replaced at the dealer. I may call them to see what kind of warranty it had.

I did the left side upper ball joint first, then moved to the right side since I had more work to do on that side. Got the upper ball joint done, got the bearing off, the drive axle out, and commenced to getting the disconnect off. Three bolts, with the upper left the most trouble due to the tranny cooler lines. Got it out since tracking showed the new was out for delivery today. Once I was down to the last bolt (upper left, of course), the disconnect slid right out towards me when I wiggled it, so I was VERY relieved! The video I watched didn't show the intermediate shaft come out with the disconnect, nor did it show any fluid leaking. I dribbled a little gear oil, but not too much. The intermediate shaft was a surprise. Then I had to wait for the mail lady. She showed up around 4:30 or so. Enough time to clean the carb on the 4 stroke mower. Gums up every winter even with Stabil. I'm going to have to start storing it dry. The smoker is fine every spring, usually starting on the first pull.

The mail lady arrived so I walked out to the mailbox to take the package from her so she wouldn't have to come in the driveway and get out. Got it opened up and put back in. Fairly easy since it was the opposite of removal and I did get it out. The drive axle was tough to get back in - I had to persuade it to go all the way in. It was also tougher to get out than the driver's side was. Anywho, got the bearing in and buttoned everything up.

The good news is that I have no more bearing noise! I haven't tested the 4WD but I'm sure the new disconnect/actuator should take care of the issue. I'll tear into the old one to see what happened to it. The front end quieted down as well. The old upper BJs were rather loose. I didn't get any movement from the lowers so I wasn't too concerned with them. The control arm bushings are a little loose but since I just rolled over 200K today, I'll monitor them and see what I need to do to keep her on the road for a couple more years if posible. I only do about 10K per year so if I can get 20K more without too much more work, I'll be happy.