Wheel bearing noise

[Razo87]

Hi everyone hopefully I could get some help with this noise I have in the jeep. It’s a 2001 sport 4x4 with 150k miles. I bought knowing the noise in the back, to me it sounds like wheel bearings.
From a stop to roll I hear the sound inside coming from under back seat. I also try with windows down I don’t hear it outside. So I go ahead and replace the rear wheel bearings and seals thats at brake drum. Test drove but noise comes back at higher speeds. Maybe 15-20mph same sound like a wheel bearing, it gets louder as I get faster but I can tune it out with radio. Currently using Valvolines 75-90 full synthetic.
Now that I have free time to dig in since my kids have break from summer school.
My tires that came with the jeep are only 4yrs old and tires appear good. I removed the diff cover and no shavings although I have replaced gear oil not that long ago from servicing the wheel bearings. Maybe less than 100 miles. I disconnected the driveshaft and I turn the pinion I don’t feel like a buckle or binding when turning the pinion. I am playing with the pinion where it bolts to the ujoint and driveshaft. Turning clockwise and counter I have the backlash sound, but if I push inward or pull I have no play, if I push it to the sides the same no play. Wanting to know if there’s another way to test the bearings? My backlash tool just bought the tool shows 0-5 play within its spec. Any more thoughts would be greatly appreciated thank you

 

[75SV1]

You could remove the rear driveshaft. Then run in 4wd. If the noise is gone, then you'd need to replace the u-joints.

 

[RCP Phx]

Don't forget to lube the output shaft splines at the same time to eliminate another item on the list, but it really sounds like a pinion bearing. What axle do you have?

 

[Razo87]

Don't forget to lube the output shaft splines at the same time to eliminate another item on the list, but it really sounds like a pinion bearing. What axle do you have?

Chrysler 8.25

 

[qianas]

Even though you didn’t feel play when pushing or pulling the pinion, the noise could still be coming from a worn pinion bearing. These bearings can wear out and cause a whining noise that changes with speed, similar to what you described. These could also be a source of noise. To check, you can remove the differential carrier and inspect the bearings and races for signs of wear, pitting, or damage.

 

[qianas]

Even though you didn’t feel play when pushing or pulling the pinion, the noise could still be coming from a worn pinion precision bearing. These bearings can wear out and cause a whining noise that changes with speed, similar to what you described. These could also be a source of noise. To check, you can remove the differential carrier and inspect the bearings and races for signs of wear, pitting, or damage.

This makes sense since a worn pinion bearing can produce a whining noise that varies with speed, which matches the symptoms described. A detailed inspection by removing the differential carrier and checking the bearings and races for any wear or damage would be a good next step to confirm if this is the cause of the noise.