2008 Outback automatic rear drive shaft issue

[bbenton8]

I am getting vibration while driving. My Haynes guide states that having vibration and noise that changes pitch consistent with speed is indicative of a bad rear drive-shaft. The Haynes guide seems to indicate that the center bearing on the drive-shaft can be replaced, but other sources dispute that.The car has only about 95k on it. Another Subaru Outback forum says to get a used drive-shaft rather than buying a new one (minimum I've seen for new is about $338). 

 

So looking for some advice if I can replace the center bearing or not, or if a used drive-shaft assembly would be OK. My understanding is this issue is rare. What range of Outback years does a 2008 drive shaft fit? Any other advice on this issue would be welcome.

 

Thanks

[Fairtax4me]

Plenty of things can cause vibration that changes pitch with speed.

A driveshaft wouldn't be first on my list. It happens, but is very uncommon.

 

Wheel bearings are the most likely.

[idosubaru]

Plenty of things can cause vibration that changes pitch with speed.

A driveshaft wouldn't be first on my list. It happens, but is very uncommon.

 

Wheel bearings are the most likely.

 

+1, i'd diagnose some more.  we can help.

 

give us exact symptoms:

 

front rear

left right

speed depednent?

temp dependent?

flat/grade dependent?

turning dependent?

noise?

vibration?

noise and vibration?

how long?

has it been getting worse?

[bbenton8]

The sound and vibration is hard to pinpoint. But to the point of possible wheel bearings, I just checked all 4 wheels. The rear wheels are solid, no play in them at all. BUT the front wheels both have play in them, pretty much the same amount of play in each wheel. 

 

I appreciate both of you for your advice. I guess the vibration from a bad wheel bearing could cause the entire car to vave vibration and noise. Looking forward to your further advice. The sound & vibration does get higher/lower based on the speed. noise and vibration? yes

how long? been a number of months
has it been getting worse? Not that I can tell

[Fairtax4me]

There should be no play in the bearings on these. Loose bearing is a bad bearing.

 

Make sure your play isn't because of ball joints or tie rod ends.

 

If the play is definitely in the bearings, make sure the axle nuts are tight. If the axle nut gets loose the bearings will be damaged.

[1 Lucky Texan]

is the vibration felt throughout the car or just in the steering wheel? any change if you coast in N ?

 

is the noise a whine, growl, hum or a rattle or a buzz....what?

[idosubaru]

There should be no play in the bearings on these. Loose bearing is a bad bearing.

 

Make sure your play isn't because of ball joints or tie rod ends.

 

If the play is definitely in the bearings, make sure the axle nuts are tight. If the axle nut gets loose the bearings will be damaged.

 

+1

 

these bearings rarely show play - that's an unlikely symptom.  it's so unlikely that i highly doubt both front bearings are bad to the exact same degree. to say it's very improbable is an understatement. 

if they are i would guess they were both previously replaced with poor bearings or compromised during installation.

 

 

could it be a tire out of balance?

[ocei77]

Another possibility is a worn u joint.

 

O.

[bbenton8]

Well there seem to be a variety of opinions and I appreciate all the input! Tomorrow afternoon I'm getting a mechanics opinion of the symptoms. I shouldn't have taken so long to get a professional opinion but as the symptoms have stayed the same for weeks I got kinda complacent. Will let ya know what the verdict is. 

[bbenton8]

The verdict is in- both front wheel bearings are the problem, my mechanic found the same thing I did, the same amount of play while moving the tire back and forth(about an inch back and forth). I also need the driver side drive axle and its boot replaced. I have them on order. Any pointers on the job I need to do? The bearings fortunately are bolt on, not press in. I have the Haynes guide which has done me well on other things I've had to do. Thanks

[Fairtax4me]

Aftermarket drive axles are know to be problematic on these. Especially aftermarket rebuilt.

FWE out in Denver does nothing but rebuild Subaru axles and does high quality work. A bit pricey but worth the cost because you get an original Subaru axle.

 

 

You can buy a CV boot kit and clean and re-grease the joint and save yourself some headache vs having to replace a cheap axle 2-3 times.

 

 

If you live in the rust belt, the bearing housings could be rusted into the knuckle. Start spraying with penetrating oil, and be prepared to get out the BFH to coax the bearing out.

 

The axle nut can be very tight. A cheater pipe may be necessary to get that loose. Again, if you live where things rust, the axle splines could be rusted into the hub.