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Whats do bad rear axel bearings sound like?

5K views 20 replies 7 participants last post by  Weebur 
#1 ·
I can't tell if its 1 bearing, both bearings or my brakes scraping or dragging. It makes a consistent scraping noise while im driving. I can jack the rear up and spin the tires and i can hear it, when i remove the brake drums it goes away....I have replaced the wheel adjusters and checked the brakes and everything looks fine. I don't smell hot breaks and there is no smoke...its driving me crazy.
 
#2 ·
theres a lip on the outer edge of the drum and backing plates... look for rust dirt build up in the groove of the drums outer lip....look at the outer edge of the backing plates see if they are bent/twisted rubbing in the groove of the drums..and are the backing plates weak/rotten...allowing them to twist/flex(no year listed)
 
#3 ·
By virtue of the fact that the noise goes away with the drums removed, you know it's not a bearing noise.

Are the brakes assembled correctly? How about the condition of the retraction springs and associated hardware? Are the parking brake cables fully released? As mentioned by others, what about the condition of the drums?
 
#4 ·
I didn't know if maybe there was something inside the diff that would make that noise also is what i meant. Im gonna pull the drums again check it out. I'll post back oh and when put my drums on are they suppose to drag a little? I always thought they were but if not maybe thats why its making noise.
 
#5 ·
Light drag is normal. It will be a slight scraping sound, but should not be heard over normal road noise even at very low speeds.
 
#7 ·
There is a whole pile of bearings in the diff. (actually, 4--two carrier bearings, and two pinion bearings.)

Is this noise only present when driving, or can you hear it if you jack up the rear end so both wheels are off the ground and you either (1) spin the driveshaft by hand or (2) put the vehicle in gear with the engine running so that the axle is spinning?

Doing the above test will help you isolate the problem. The first thing I would be looking at is a u-joint on the drive shaft. When they dry out, that can sometimes make grinding/scraping type sounds.
 
#8 ·
When you say it makes noise with the brake drums on do you mean with the rim attached, or did you put the drum on and bolt it down without the rim, and let it spin? You might try it with the drums bolted down no rims, and see if it makes the same noise. And you might also put the rims back on and lift one side and with it running in gear see if the lifted wheel side makes noise, and do the same on other side. When it is running if it is in brake/bearing area you'll be able to hear it, if not on sides you'll be able to hear it in the center. It is possible that when you have no load on the rear end (with the drums off there is no drag from the brakes) that the noise does not show up. Put a load back on the rear end and if it is a bearing or U-joint noise it should show up right away.
 
#9 ·
Rear axle noise will start around 15 MPH and not go away. Leave your rear hatch slightly ajar and it will be even louder. It will need a bearing kit and profesional set up to quiet it down.
 
#10 ·
The sound is coming from the center while driving. I sat in back and let my dad drive so i could pin point the sound .Im gonna grease the u-joint 1st then go from there. If it inside the diff. how much would a rebuild or repair cost? or would it be cheaper to buy a junk yard diff?
 
#12 ·
I am confused. First you said the noise was only present when the brake drums were in place.

Now you say you hear nothing when you spin the drive shaft, but you hear tooth engagement.

So what noise would you hear that goes away when the drums are removed? The gears mesh the same with and without the drums in place....

Have you jacked up the rear and put it in gear with the wheels elevated? What noises to you hear then?

Have you checked for sloppy u-joints?

Is you axle leaking/seeping any fluids?

Is the axle full of lube?

Have you removed the axle cover and inspected the lubricant for signs of metallic particles in the lube?
 
#13 ·
I'll start from scratch.

Broke 1 of my e-brake cable and thought that cause the noise
Changed the e-brake cables and adjusted it, Noise still there
Took apart and inspected the rear brake setup replaced the adjuster screws and removed all the rust from the inside of drums. Noise still there
Turned wheels with drums and hear a light scrape. Removed wheels and drums and no scrape, Its not the wheel bearing and the scraping is normal brake noise for rear drum brakes.
Turned drive shaft with/without tires and drums, Light scrape with drums. No scrape without drums
Can feel gears when i spin the axles shafts and drive shaft.
Noise seems to be coming from the center of the axle while riding in the back seat.
Driveshaft dosn't move up and down only rotates left and right like its suppose to.
Changes the fluid and found metal shavings.

So now im convinced its a bearing. Just not sure which one and need help deciding on what i should do.
Junkyard
Try rebuilding myself
Paying someone to rebuild
 
#14 ·
The scraping sound may be coincidental and unrelated to the issue you describe.

So my next question--did you pull the axle shafts and look at the wheel bearings and the portion of the axle upon which the ride? If all of that is good, then your issue is in the diff. bearings.

So next question---does the noise change when the axle is under load, or coast, or "float" (neither load or coast)? If not, then it's probably a carrier bearing. If so, then it's a pinion bearing.

If you decide to fix this yourself, you need to study up on how to set up gears, since that will be what you need to check after change the bearing(s).

The other choice is to get an junkyard axle (make sure it's the SAME axle ratio as you have now), and swap that out. It's probably going to be easier in terms of technical difficulty, but more hassle in terms of actual work.
 
#17 ·
Took it to a guy yesterday and let him listen to it and he said its nowhere near the point of tearing it down and rebuilding it. We opened it and he checked it out real good and nothing was loose or binding or anything. We did find some tiny specs of metal, it was pretty much like glitter so he sprayed it down with kerosene for about an 1 and cleaned it up real good. We refilled it
with lucas 80-90 and some lucas oil stabilizer for diffs and trans cases.
 
#19 ·
old thread but maybe someone will see this. I have a sound coming from the back almost like a tire rubbing but its not. Its not a clunking.it gets loud when you get to about 15mph and gets louder the faster you go. Putting it in neutral doesn't make a difference. i have no play in the tires but i havent ruled out wheel bearings. When i have it jacked up and someone puts it in drive the noise is pretty much gone. Does that mean i can rule out pinion bearings because thats been what i was thinking. Any suggestions? thanks
 
#21 ·
Just some general info on bearing noise:

Pinion bearings have a high pitch noise (because the pinion gear rotates faster than the carrier). Drive the vehicle and put it under load, if the noise occurs the source is the rear pinion bearing. If the noise occurs while coasting then the front bearing is the source.

Worn carrier bearings usually produce a low pitch noise that is usually present constantly and varies only with vehicle speed.

Axle shaft bearing can produce vibration and noise that will change when the bearings are under load. To check, drive the vehicle and turn sharply to the left and right. This will load one side and unload the other. The noise on the side that is under load will increase, conversely, the unloaded side noise will decrease or go away. When the damage is slight the noise will usually not be noticeable at speeds above 30 mph.
 
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