Rear Wheel Bearing Check with Removed Axles

[Four-CLT]

I've been having a low growling/wha-wha-wha noise coming from my vehicle for several months now.

I checked the following with no avail:

Front Wheel Bearings
CV Shafts
Drive Shafts/U-Joints
Differential

I think I finally found the culprit when I lifted the back end of the vehicle and observed play in the driver's rear wheel. Also when you spin this wheel, there is a slight scaping sound every revolution and the spin noticeably slows down with the noise. Bad wheel bearing?

If so, I found a few low-mile axles at local scrap yards for cheap. My question is: Are there any ways to check the bearings when the axle is off of the vehicle? I don't want to buy a used axle only to find out that the bearing is bad as well.

 

[Nelsonmd]

You can check the wheel for signs of leaking gear oil, which suggests the seal blew and washed out the bearing. Also look for gear oil behind the axle, outside of the seal, again to make sure the seal never leaked.

Otherwise, you might be able to look directly at the bearing as see evidence of either grease spewing out a little bit, or if it looks like it has been washed clean by gear oil. If you take a screwdriver, chisel, etc. you might be able to pry the bearing seal up to see if the grease is still in tact, but that may damage/stretch the seal, so I probably wouldn't do that.

 

[Four-CLT]

That makes sense. Is there any way to test for play with the axle off of the vehicle?

 

[nevada]

That makes sense. Is there any way to test for play with the axle off of the vehicle?

not really. even a new/good bearing will have some play when its off the truck. it doesn't really make sense, but they tighten up when installed.



why not just have the bearing replaced on your axle? then you know its good.

 

[Four-CLT]

Just trying to save a few bucks. This option is much less expensive than buying a bearing, 2x retainers, ABS rotor, axle seals, and having someone press it on. I figure even if the new-salvage axle doesn't pan out, I would still have an extra axle to do the new bearing install and still have a driveable vehicle.

 

[Diesel_Dog]

Before you remove the axel, you could remove the ABS sensor (10mm bolt I believe) and have a look at the ABS ring. If it's wet with gear oil that's a good sign that the seal and bearing is bad.

 

[Drcoffee]

I've been having a low growling/wha-wha-wha noise coming from my vehicle for several months now.

I checked the following with no avail:

Front Wheel Bearings
CV Shafts
Drive Shafts/U-Joints
Differential

I think I finally found the culprit when I lifted the back end of the vehicle and observed play in the driver's rear wheel. Also when you spin this wheel, there is a slight scaping sound every revolution and the spin noticeably slows down with the noise. Bad wheel bearing?

If so, I found a few low-mile axles at local scrap yards for cheap. My question is: Are there any ways to check the bearings when the axle is off of the vehicle? I don't want to buy a used axle only to find out that the bearing is bad as well.

You are jumping the gun here. The intermittent rubbing sound is probably your drum brake shoes. It sounds like the drum is out of round. A quick check would be to drive around and after 15 minutes, hop out and carefully touch the brake drum with your hand. Compare left to right side. If the drum is too hot to touch, the shoes are rubbing the drum. Why? is the question. The axle seal may be leaking and causing the shoes to swell. Or more likely, the parking brake cables or pivots are rusted and not fully releasing. Pulling the axles and spending $400 in parts would not be my first step. After feeling for excess heat, pull the wheel and drum off the hot side and see what going on. If you have to fix the seals, do both at the same time and read my thread "possible solution to leaking..." There's another thread out there that has good pictures too.

A bad bearing tends to get louder as you turn one way or the other and quiet down in the reverse. A really bad bearing will generate heat in the wheel hub. So if the drums are cool and the same from side to side, feel the center hub of the wheels. Again, if one is hotter than the other, you know which side to address. Unless you are hotrodding around town, the rear brakes should be warm to the touch, not hot. If cold, the pads may not be touching the drum at all.

If its the bearings, it wont make the rubbing sound at the same place in wheel rotation. So for example, if the rub hits as the air valve is at 12 oclock on every rotation then think brakes. If the rub is rhythmic but at different points in rotation as the wheel spins, think bearing. The reason for this is the ball bearings are rolling in the race so they are not at the same place during each rotation.

 

[Four-CLT]

You are jumping the gun here. The intermittent rubbing sound is probably your drum brake shoes. It sounds like the drum is out of round. A quick check would be to drive around and after 15 minutes, hop out and carefully touch the brake drum with your hand. Compare left to right side. If the drum is too hot to touch, the shoes are rubbing the drum. Why? is the question. The axle seal may be leaking and causing the shoes to swell. Or more likely, the parking brake cables or pivots are rusted and not fully releasing. Pulling the axles and spending $400 in parts would not be my first step. After feeling for excess heat, pull the wheel and drum off the hot side and see what going on. If you have to fix the seals, do both at the same time and read my thread "possible solution to leaking..." There's another thread out there that has good pictures too.

I agree with your thoughts on the shoes dragging. One of my assumptions was that the bearing slop could be causing the shoes to be off-axis relative to the drum, resulting in the drag.

Just for clarification: Would this fluid leak occur without a visual indication from the outside? All of the leak threads that I've seen show the fluid spray on the back side of the backing plate.

 

[Nelsonmd]

Yeah, good point, those symptoms sound like a dragging drum, which is very common and may not even be a problem.

My failing rear wheel bearing gave a cyclical hum/whine while driving along with some vibration. I lifted the rear end and spun each wheel individually and could feel/hear the cyclical hum. You could also take the wheel and brakes off and spin the axle freely, but that is more work than is necessary.

 

[Drcoffee]

I agree with your thoughts on the shoes dragging. One of my assumptions was that the bearing slop could be causing the shoes to be off-axis relative to the drum, resulting in the drag.

Just for clarification: Would this fluid leak occur without a visual indication from the outside? All of the leak threads that I've seen show the fluid spray on the back side of the backing plate.

Bearing slop = brake shoe rub? The bearings would be completely gone in order to get that much movement. I dont think that would be likely.

Good question. The gear lube would have to migrate from the housing, thru the bearing, fill the outer dust seal and then spray onto the drum. So it can takes days to months to migrate that far depending on how long and how bad its leaking. Carefully pop the ABS sensor out and look inside. You can do this while the wheels are off. Here is what you would see: wet or dry.

Wet

Dry
<iframe width="420" height="315" src="http://www.youtube.com/embed/Z41ZYnb940c" frameborder="0" allowfullscreen></iframe>

 

[Four-CLT]

I think I will slip the drum off and peek through the ABS sensor port later this week.

Like I said before, this noise has been going on for some time. I thought it was from the worn out tires I was riding on, but now I have new tires and it's doing the same thing.

 

[Nelsonmd]

I agree with your thoughts on the shoes dragging. One of my assumptions was that the bearing slop could be causing the shoes to be off-axis relative to the drum, resulting in the drag.

Just for clarification: Would this fluid leak occur without a visual indication from the outside? All of the leak threads that I've seen show the fluid spray on the back side of the backing plate.

If it's a bad leak, then yeah, it should show from the outside. What I meant was when you go to the salvage yard, you should look for those signs of a seal leak on a potential donor vehicle to make sure you don't get another bad bearing. This is a common issues, and this is another reason to replace the bearing yourself.

 

[wc11]

Here's what a noisy almost dead rear bearing sounds like.
https://www.youtube.com/watch?v=Qc3tnFbCK48

 

[Four-CLT]

Here's what a noisy almost dead rear bearing sounds like.
https://www.youtube.com/watch?v=Qc3tnFbCK48

Thanks for that link! That sound is very distinctive for sure. I will add this test to my list of checks to do this week.

 

[Four-CLT]

I did some checking tonight. The results:

Lifted Rear Drive Test - No noise remotely like the video clip at speed.

Removed Brake Drum - Shoes were very tight (which may explain some of the drag). Some signs of previous moisture, but nothing dripping. Shoes and drum surface were both completely dry. I readjusted the parking brake while I was at it.

ABS Sensor Port Inspection - Driver side is wet, passenger is dry. I'm going to partially remove axle, clean and dry the components, reinstall, and recheck in a couple of weeks. I'm not convinced yet that the leak is active. Last year when I swapped my differential. The axles leaked a bit after a test drive because I didn't torque the axle nut enough. The tutorial I was using said 39 ft-lb instead of the 59 ft-ib needed. I retorqued and the leak stopped.

I'd rather make sure before I star tearing things apart too much.