strange howling noise 1999 outback

[olivia123]

I have a 1999 outback wagon auto trans with about 170,000 miles. I have a new strange noise that I will describe as a kind of howling that pulses or osculates. The sound occurs only when going up fairly steep inclines at speeds between 40 -65 mph. It stops if you lift off of the accelerator. It sounds like something from the drive train somewhere.

 

I first noticed this about a week after I did the 3 times transmission fluid change. I just checked the fluid level and it is OK. Any chance there is a connection?

 

My guesses range from a bearing somewhere in the drive train perhaps in the tranny to maybe a wheel bearing. I’m thinking bearing since it makes the noise under a higher load. Could it be a cv joint? Hope hope.

 

I would appreciate any insight that you folks may have.

[TahoeOutback]

"howling" is typically used to discribe bad wheel bearing. Jack up the car and rock the wheels. See if there is any play. Rock the wheels with your hands in the 12 and 6 o'clock position, so that you do not feel any steering tie rod (or toe aligment joint) play.

 

I should add that sometimes a bad wheel bearing only howls but does not jiggle/rock.

Edited April 3, 2011 by TahoeOutback

[Suba9792]

if it only is doing it going up hills its most likely not wheel bearing related be as the OP said it could be trans trouble, any codes?

[olivia123]

No check engine light, but I assume you meant trans codes? I don't know much about these or how to read them. I'm going to put the FWD fuse in today and drive the same roads and see if there is any change. Thinking maybe rear diff. I'll update then. Will also check for play in the wheels as suggested.

[olivia123]

Update: I drove car with the fuse in, so FWD, and was able to find a hill where I could replicate the conditions that caused the noise easily. It made the noise in AWD and DID NOT in FWD. I tried it several times and the results were the same each time.

 

I wonder what this tells me? Something in the rear diff? I have read various accounts of driving these subarus with the fuse in, FWD. They range from drive it forever no problem to not more than 5 miles and then slowly and just about everything else in between. There is also discussion about removing the back section of drive shaft with the fuse in and the fuse out. Is there a link to a good discussion of this topic?

 

I just want another year or so out of this car and would be more than happy to drive it FWD only if that is an option.

 

Also checked for play in wheels and found none. Couldn't break the fill plug in the rear diff to check level but sprayed with PB and will try again later.

[Suba9792]

Its possibly the duty C solenoid or clutch pack. Look both up on the board to be honest I'm not positive on it. BTW Highly doubt its the rear end.

[Gloyale]

Possibly the bearing that supports the transfer clutch hub. Easy to replace by removing tranny tailshaft.

[olivia123]

Update: The noise is now showing up in more situations, less steep inclines and some times even on flat roads. I had someone sit in the back seat and listen and they said the noise was definitely coming from the pass side wheel well area. I then sat in the back while some else drove and also think the noise is coming from the rear passenger side.

 

Is the any chance that this could be a wheel bearing? There is no change in sound when turning but it does stop when you lift the accelerator which doesn’t seem like a wheel bearing symptom.

 

BTW noise still not present when in FWD.

[Suba9792]

Even with the fuse, a wheel bearing will still make the noise as the wheel is rolling. My guess would be either rear diff carrier bearing or the TC.