Bearing noise I can't seem to find

[02Lightning]

I have a bearing noise I can't seem to find, Denali has about 144k on it now. I thought was in the rear end, so I pulled the axel's and replaced the outer bearings, no change. The noise doesn't change when turning or putting it in neutral when driving. The noise starts about 30 mph. I also changed the front differential and transfer case fluid, neither was low and very little metal and or sludge. Any ideas?

 

[Geotrash]

I have a bearing noise I can't seem to find, Denali has about 144k on it now. I thought was in the rear end, so I pulled the axel's and replaced the outer bearings, no change. The noise doesn't change when turning or putting it in neutral when driving. The noise starts about 30 mph. I also changed the front differential and transfer case fluid, neither was low and very little metal and or sludge. Any ideas?

2WD or AWD? It's quite possibly a front wheel bearing. I've had them start to go bad and not have any change when turning. If you're sure it's coming from the rear of the vehicle, another possibility is the pinion bearing, but that's pretty rare on one of these.

 

[02Lightning]

2WD or AWD? It's quite possibly a front wheel bearing. I've had them start to go bad and not have any change when turning. If you're sure it's coming from the rear of the vehicle, another possibility is the pinion bearing, but that's pretty rare on one of these.

AWD, I'm not really sure it's coming from the rear of the vehicle, it kinda sounds like it. The front wheel bearings have about 45k on them (timken), and when I noticed them, they would change sounds when turning. I've heard pinion bearings before, and they would change sounds when giving gas or letting off. That's kind of the reason I ruled those out, but who knows. I had it into a mechanic about a month ago for something else, and he said he thought it was in the rear end, but would have to disassemble and inspect to be sure.

 

[Geotrash]

AWD, I'm not really sure it's coming from the rear of the vehicle, it kinda sounds like it. The front wheel bearings have about 45k on them (timken), and when I noticed them, they would change sounds when turning. I've heard pinion bearings before, and they would change sounds when giving gas or letting off. That's kind of the reason I ruled those out, but who knows. I had it into a mechanic about a month ago for something else, and he said he thought it was in the rear end, but would have to disassemble and inspect to be sure.

I haven't had a pinion bearing go on one of these trucks, but I did on a Land Rover and it made noise regardless of throttle position. I reckon the best thing I can suggest without being able to hear it is to take it to a shop that has a set of chassis ears. That's how I narrowed down the cause on the Land Rover. I think I spent $150 for the diagnosis.

 

[OR VietVet]

I have a noise from the rear that sounds a little like a bearing noise, that I cannot hear with the radio on. It turns out that the noise is normal gear lash noise and have changed fluid and no difference and the noise is not constant until after about 25 mph and does get a ltlle louder to a point at higher speeds. I have used a dial indicator and the gear lash is right in the middle of the specs. Yours may be that but would have to hear yours to see if compares. Good luck in the search. Could it be the transfer case and fluid there since is AWD?

 

[02Lightning]

Maybe I'll have someone get it on a lift, put it in gear and do about 30 to 40 mph and see if they can track it down with a stethoscope. I have had this vehicle from new, and this is a new noise.

 

[OR VietVet]

You want to do that on a drive on rack and then lift so that the suspension is loaded and not hanging down on a regular lift.

 

[Foggy]

Exactly what OR VietVet said.. Has to on the road driving..
Change your diff fluid and see how it reacts.. If it's getting louder over time and
is louder with +MPH, then prob the ring/pinion gear

 

[02Lightning]

Exactly what OR VietVet said.. Has to on the road driving..
Change your diff fluid and see how it reacts.. If it's getting louder over time and
is louder with +MPH, then prob the ring/pinion gear

I changed the fluid when I pulled the axels and replaced the outer bearings. It's doesn't seem to get louder the faster I go, it just shows up about 30 or 40 MPH.

 

[Foggy]

Sounds like ring/pinion gear to me.. but that's an internet diagnosis !!