Brand new wheel bearing bad, or something else?

[PC_GUARD]

Ive always had a slight decel whine, which ive accepted as just nature of the beast. About a month ago I still had one wheel bearing to replace on the car, so finally got around to swapping it. Did about 700 mi road trip and noticed some noise but nothing substantial, but now I do notice the noise on decel.

It acts like bad gear setup, but not nearly as severe. Its not exactly a gear howl, as much as a whine. No torque and just coasting dead silent, in gear ill have noise.

The car has 69k miles on it and I am 99% sure I read somewhere in the cars history a dealer swapped out the rear entirely, early on in its life.

Can torque load make a bearing flex, or toe change enough to flex the bearing to create the whine? Or should I do a dif service and cross my fingers its not a pinion depth issue (crush sleeve) slack pinion preload?

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[ORRadtech]

I don't have a specific answer to your question, but, if the noise got worse after the new bearing then I'd suspect it as well.
Was it a Ford bearing or aftermarket? There have been tons of QC problems with aftermarket parts in the last 18 months or so.
I know that aftermarket lifters and cams have been particularly bad so it's certainly in the realm of possibility that a new bearing is bad.

 

[PC_GUARD]

I don't have a specific answer to your question, but, if the noise got worse after the new bearing then I'd suspect it as well.
Was it a Ford bearing or aftermarket? There have been tons of QC problems with aftermarket parts in the last 18 months or so.
I know that aftermarket lifters and cams have been particularly bad so it's certainly in the realm of possibility that a new bearing is bad.

It was a new timpkin, I'll order an OE and swap it out.

 

[Cobra Jet]

It was a new timpkin, I'll order an OE and swap it out.

Timken is actually one of the best bearing companies out there - and I've never had an issue with any type of bearing assembly manufactured by them. It's not to say it can't happen, but it's pretty rare having a bad Timken product.

Are you certain that the noise isn't coming from another bearing/hub assembly or even elsewhere, like bad tires, rear pinion or the driveshaft center bearing assembly?

 

[PC_GUARD]

Timken is actually one of the best bearing companies out there - and I've never had an issue with any type of bearing assembly manufactured by them. It's not to say it can't happen, but it's pretty rare having a bad Timken product.

Are you certain that the noise isn't coming from another bearing/hub assembly or even elsewhere, like bad tires, rear pinion or the driveshaft center bearing assembly?

Me either thats why I was comfortable with buying 4 timpkins.

I'm not 100% sure. Decel is noisy, but its different than bad gear assemblies, or low fluid/gear noise. It's less grind/whir sound and more like a tire howl, but zero noise clutch in.

A jack shaft bearing I'd assume would change sounds with turning.

I should add: For whatever reason the noise seems focused from the drivers side and not noisy through the car. I do not have any aftermarket dif bushings, just the bmw bracing and toe bearings. So I havent anything to suddenly add NVH, everything has been installed for months. The reason for the bearing swap was they were all noisy as hell. The sound had always been there, but still had this last one to do and hoped it would quiet it down. On the road trip the same faint noise was still present, but is now louder. Loud enough where my girl asked wth the sound is.


My fear it's a pinion depth issue.

I ordered a Motorcraft replacement, so we'll see.


Another thought i had is, (this is my first torsen dif) that I have dirty dif fluid?

 

[Cobra Jet]

Me either thats why I was comfortable with buying 4 timpkins.

I'm not 100% sure. Decel is noisy, but its different than bad gear assemblies, or low fluid/gear noise. It's less grind/whir sound and more like a tire howl, but zero noise clutch in.

A jack shaft bearing I'd assume would change sounds with turning.

I should add: For whatever reason the noise seems focused from the drivers side and not noisy through the car. I do not have any aftermarket dif bushings, just the bmw bracing and toe bearings. So I havent anything to suddenly add NVH, everything has been installed for months. The reason for the bearing swap was they were all noisy as hell. The sound had always been there, but still had this last one to do and hoped it would quiet it down. On the road trip the same faint noise was still present, but is now louder. Loud enough where my girl asked wth the sound is.


My fear it's a pinion depth issue.

I ordered a Motorcraft replacement, so we'll see.


Another thought i had is, (this is my first torsen dif) that I have dirty dif fluid?

So if it's a wheel bearing at any corner, usually when they go bad you will get the growl, or the feeling of driving over pebbles/rocks. However, as you are driving if the car leans into the bad bearing, the growl or howling will usually get louder as the load transfers. So going into curves or corners you should hear (and feel if really bad) the side where the bearing is faulty.

Jack up one side of the car - grasp a wheel at the 12/6 o'clock position and pull/push - do the same at the 3/9 o'clock position - pull/push. Do you feel any excessive wobble or hear a clunk? That's the best way to determine a bad wheel bearing.

If the problem is the rear diff - the growl or howl will increase in speed/rpm as well as drivetrain load. If you let off the clutch (if manual trans) or accelerator and the sound decreases, but increases again with load and during speed/rpm increases - there's an issue with the rear diff (most likely pinion bearing).

 

[PC_GUARD]

So if it's a wheel bearing at any corner, usually when they go bad you will get the growl, or the feeling of driving over pebbles/rocks. However, as you are driving if the car leans into the bad bearing, the growl or howling will usually get louder as the load transfers. So going into curves or corners you should hear (and feel if really bad) the side where the bearing is faulty.

Jack up one side of the car - grasp a wheel at the 12/6 o'clock position and pull/push - do the same at the 3/9 o'clock position - pull/push. Do you feel any excessive wobble or hear a clunk? That's the best way to determine a bad wheel bearing.

If the problem is the rear diff - the growl or howl will increase in speed/rpm as well as drivetrain load. If you let off the clutch (if manual trans) or accelerator and the sound decreases, but increases again with load and during speed/rpm increases - there's an issue with the rear diff (most likely pinion bearing).

no end play I checked it when i did brakes last week but none of the bad wheel bearings had bad end play, just noisy as all hell.

The noise I hear at highway speeds (around 75 ish) is a slight hum, but not crazy or unusual for this kind of setup (my sn95 with 410's with a locker was much more prevalent) the main noise is putting decel torque on but doesnt get louder and is more noticeable at city speeds.



I wonder if the yoke/dif angle is sloshing around, putting pressure on the pinion in a weird way. But again i only hear it come from the driver side. I guess I'll just have to tear it apart. Ill do a fluid swap today and see

 

[PC_GUARD]

Ok did a fluid change with Motorcraft and friction modifier. Quieted everything down a bit.

Here's what I've determined: I replaced rear pads with stoptec z26 pads and they're touching enough to amplify the nvh from the driveline. The little bit of noise I've always have had, is just being amplified.

So far I'm not impressed with the power stop brakes. The noise on the front was so bad I put on Napa semi metallic just to get by until I order oe pads.

I'll tear the back apart and add more grease on the backer side, maybe that'll numb it up.

I'll report back

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