Drivetrain Bearing Noise - Where to Look Next?

Good Morning TahoeYukon Folks,
I am in the process of plotting my next move to track down some drivetrain noise on my 2009 1500 XL 5.3. Just rolled over 99,000 Miles.

I was hearing some excess road noise and correctly assumed that my front hubs/bearings were toast, so I replaced those, and my driver's side CV axle while I was there. It reduced the bearing noise I was hearing but did not eliminate it. The noise I'm hearing I would describe as an almost skateboard like noise combined with a knobby tire like drone (but not nearly as loud as someone actually driving by with aggressive tires) that comes on about 30-35mph and is very noticeable to me at around 50-60mph. The noise does not increase or decrease with load like I've experienced in the past with a bad rear end, and I can't seem to make it increase or decrease by loading one side of the car vs the other around a bend. Also having a difficult time determining which side its coming from by driving next to jersey barriers on either side.

So I'm looking to decide what to attack next. Here's my plan so far:
1. Rear wheel bearings: I'm on my original rear axle/wheel bearings, and one of my axle seals has a slow weep affecting e-brake hold so I want to knock those out next. Since they've got 100K on them this won't be wasted time no matter what. Inspect rear diff while I'm in there. I don't think the rear diff is the issue because in my experience a failing rear diff increases its noise significantly under throttle and also is much more of an aggressive high pitched whine/buzz, but I'll check out what I can see and look for metal in the gear oil.
2. Inspect U-Joints: I thought this would cause more of a clunk but apparently these can whine and roar as well.
3. Inspect front diff & bearings: According to google AI apparently these bearings can wear and make noise without any noticeable vibration when driving. Could use some input here because in the 5 GMT900s we've had in our family none of them have had this issue.
4. Check alignment: I haven't had the alignment checked on this rig in the 30,000 miles I've had it, but the bridgestone duelers I had on there before the michelins I just put on were wearing very evenly with 7-10k rotations so I never felt the need. Also I'm putting this off becuase I want to replace my struts, ball joints and tie rod ends as part of my 100k maintenance

Is there anything else I should go after that could be making this bearing noise?

I recommend that you take the truck to a trusted local repair shop, and get the truck on a lift with the wheels off the ground and with someone inside the truck. Put the truck in gear and press the gas pedal a bit, and see if the noise also occurs in the unloaded situation (wheels off the ground). If the noise still occurs, then the Mechanic underneath the truck can go around, with a stethoscope if necessary, and locate the source of the noise.

There's a lot of possibilities.... Getting it in the air with someone underneath and save you shooting the parts cannon at it.

The front and differentials in these, usually it's the pinion that goes first with the characteristic whine at highway speeds on light throttle, that goes away when you let off.

Rear axle bearings usually go for a lot longer than 100,000 miles.... But yeah, a leaking seal raises questions.

Do you change your transfer case fluid regularly? It doesn't hold much, inexpensive to change.... And a look at what drains out can be useful. Same goes for the front differential.

U-joint bearings tend to last a long time as well. Changed all mine at 172,000 miles just because.... They still had decent grease in them.

did you do both from hubs? also they don't last very long. I think mine is going out again. only a year later. oem one too.

before digging into stuff. I recommend a mechanic ear setup. you clip them on different things around the truck. go for a drive and switch between them. little. prices, but honestly all replacement parts are awful quality these days. if you saves you removing one oem part that would have lasted a life time. only to use a replacement that goes bad all the time or worse makes you chase your tail. it's worth it., or was to me.

I have these... but there's a bunch of different brands and much cheaper if you go wired..


also, you have 4wd is it the time with 2wd, auto 4hi and 4lo? I found if I leave mine in auto it makes a noise too. I just use 2wd unless I think I might need auto for some reason.

Where does it sound like it's coming from? Front or rear? Under ur seat? Does it change when u steer side to side as u are rolling? Remove the front drive shaft and drive. See if it quits or is not as loud. If it's not as loud then in the chunck u go.

Thanks everyone for the input. I do have PA state inspection coming up shortly so when I schedule my appointment I will see if the shop will charge a diagnostic fee or similar to investigate this while they have it up on the lift.

rdezs said:

Rear axle bearings usually go for a lot longer than 100,000 miles.... But yeah, a leaking seal raises questions.

Do you change your transfer case fluid regularly? It doesn't hold much, inexpensive to change.... And a look at what drains out can be useful. Same goes for the front differential.

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Agreed on the rear axle bearings. Unfortunately that passenger seal is leaking and causing my e-brake to hold poorly, and I need it to work well because on my current property I have to park on an incline when I hook up and store my boat. So if I'm draining my rear diff to do that seal I'm going to replace both bearings and seals on both sides. Added bonus of being able to look for metal confetti in the fluid I guess?

For the transfer case I can't really say I change it "regularly" but when I bought the truck 2.5 years and 30,000 miles ago I changed every drivetrain fluid (front and rear diffs, transfer case, and trans) to Amsoil. Barring any issue I would usually let these go to 50k miles for the t-case and diffs and change the trans every at 30-40k.

j91z28d1 said:

did you do both from hubs? also they don't last very long. I think mine is going out again. only a year later. oem one too.

also, you have 4wd is it the time with 2wd, auto 4hi and 4lo? I found if I leave mine in auto it makes a noise too. I just use 2wd unless I think I might need auto for some reason.

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I did do both front hubs. The passenger side failed during a road trip so I bought the part at Advance Auto and had it done at a local shop, and then bought a second one and swapped the driver's side myself when I got back. Unfortunately got the "carquest" brand because that's what was available immediately.

I run my truck in 2wd all the time but I have messed with switching it in and out of 4hi and it doesnt seem to affect the noise, or at least it wasn't a "lightswitch" difference. I rarely use 4 Auto but I could try that as well, though I suspect I will just hear the front driveshaft spinning in addition to whatever this noise is.

yeah, it was only a thought if you drive in auto all the time you might hear something like I do. but if your 2wd all the time then not worth messing with.


I have a feeling one of your replacement hubs when bad

rear bearing can be difficult. there's threads around here about removing them without. messing up the abs sensor right behind it. I myself had a seal leaking, I did new seals and timkin bearings while in there. should be a good brand name but they didn't work out. still had the oem bearings laying around, so stopped by the dealer for 2 new seals. put the 150k bearings back in. new seals and at 185k now still good back there. with some light towing.


I preach to everyone. less is more in this era of bad quality replacement parts