Humming Noise when accelerating and under load

[virafp]

For the past 2-3 months, there is a humming/low frequency sound, that appears to be coming from the left front. It is louder when accelerating, and does away as the trans shifts gears, and then reoccurs as you accelerate under increased RPM's. At cruising speed it is not there. However as you accelerate, you do hear it. Seems tied to shifting and engine RPM. Seems more pronounced on uphills?

Trans was serviced 5000 miles ago, and shifts very smoothly, both upshifts and downshifts. No slippage at all. Noise has not gotten any louder. No vibration in th floorboard, and normal slight vibration in the shifter, same as when the truck was new.

Seems to occur under load while accelerating. No noise at cruising speed in OD.

Any thoughts? Thanks

 

[SupraTuRD]

Are your front wheel bearings/needle bearings in good shape?

 

[virafp]

Bearings

Are your front wheel bearings/needle bearings in good shape?

Probably should have them checked since I am at 187K. They have never been replaced. What's the best way to check them? Thanks

 

[OregonLC]

Is it RPM-dependent or speed-dependent. That is, do you always get the same noise at say 2,200 RPM regardless of vehicle speed? If so, it's not your wheel bearings.

The left-front is curious as there's nothing rpm-dependent there. However, noises travel funny in vehicles. I would have thought drive shaft, t-case, or differential.

 

[paflytyer]

Probably should have them checked since I am at 187K. They have never been replaced. What's the best way to check them? Thanks

Wouldn't hurt to repack them. It's loooong past due if you've never done it. If you lift the wheel, is there any play from the 12-6 o'clock or 3-9 o'clock positions?

 

[Old#7]

Had something similar, ended up being rear drive shaft ujoints. Changed them out and noise is gone.
As was mentioned noises travel funny through vehicles.

 

[virafp]

RPM or Speed

Is it RPM-dependent or speed-dependent. That is, do you always get the same noise at say 2,200 RPM regardless of vehicle speed? If so, it's not your wheel bearings.

The left-front is curious as there's nothing rpm-dependent there. However, noises travel funny in vehicles. I would have thought drive shaft, t-case, or differential.

The best I can describe - uphill or on acceleration, a bit harder than normal, start to hear the hum/drone/whine, car upshifts, noise goes away as you move into another gear and the engine RPM drops. Step on it again, hear the same noise when it downshifts. Basically, it happens when you put some load on the engine/transmission and when it downshifts. Tranny shifts fine. Recent work done was new front hubs.

 

[virafp]

Bearings

Wouldn't hurt to repack them. It's loooong past due if you've never done it. If you lift the wheel, is there any play from the 12-6 o'clock or 3-9 o'clock positions?

Bearings have never been replaced, but they were serviced 7000 miles ago.

 

[virafp]

Update

Put 4 new tires on today, noise is slightly less, tomorrow we install a new radiator, and replace the differential fluids and transfer case fluids.

 

[cruiser03]

I had the same thing happen. Changed the transmission mount. Big piece of rubber, they go bad starting at about 8 years if you live in any kind of heat. Fixed it immediately. Also my truck would creek a little around corners, replace the upper/lower control arms and panhard rod, those old rubber bushing were not centered any more - all quiet now.

 

[smileyboy]

Just started hearing a low rumble noise coming from the front under acceleration. Hope that's all it is... Also a clicking noise when suspension flexes..

 

[mrbigboy]

I've got the same thing on mine. Good info, thanks for posting.

 

[Mach5]

I had a very similar sounding thing on my other vehicle recently. Drone and rumble under low rpm, high torque acceleration. It would vanish at highway speeds and wasn't noticeable when not under load. It turned out to be a very damaged cv joint that had been replaced previously and not torqued to spec on the install. It was obvious when we got the car up on a lift. You could see the whole half axle vibrating as it got up to about 60kph. Just another thought to complicate things for you...

 

[Somebodyelse5]

Did you ever find a solution your noise?

I installed a 2.5" lift this weekend and the noise started.

Makes me think its something CV related.

 

[Freddyfoxx]

Hi guys, I've had this noise:
Have 203K miles on it. Would appreciate it if you can help. It happens when the temperature is hot outside like above 90C. It happens at highway speeds. It sounds as if I'm riding on off road or oversized tires but mine are standard Michelins. thanks in advance.

 

[LittleRock80]

Hi guys, I've had this noise:
Have 203K miles on it. Would appreciate it if you can help. It happens when the temperature is hot outside like above 90C. It happens at highway speeds. It sounds as if I'm riding on off road or oversized tires but mine are standard Michelins. thanks in advance.

I've got this noise (on the video) now. Only does it briefly while turning right and accelerating up one certain hill. Does not make the sound constantly like in the vid at highway speed. Hoping it's not transmission related (2001 LC).

 

[AlpineAccess]

Sounds like u joints.

 

[nissanh]

Did you notice it after a repair? I has a small humm right at 82 MPH from front passenger side. I think it is from my non-oem CV.

 

[LittleRock80]

Just had the transmission fluid exchanged at the dealer (232K). It made a difference. It shifts faster into Drive, shifts smoother, and I gained another 1.5 mpg. Odd thing is, my driveway is the same grade as this hill, and no noise.

I'm going to try new oem ujoints as suggested, grease the prop shafts, and cross my fingers.

 

[AlpineAccess]

Just had the transmission fluid exchanged at the dealer (232K). It made a difference. It shifts faster into Drive, shifts smoother, and I gained another 1.5 mpg. Odd thing is, my driveway is the same grade as this hill, and no noise.

I'm going to try new oem ujoints as suggested, grease the prop shafts, and cross my fingers.

Try pulling one shaft at a time and locking c diff to isolate which driveline it's coming from.