I have a 97 Legacy Wagon 2.2 with automatic transmission (AWD)

 

I have a noise that is generated from the front passenger side. It is a cyclical noise. The noise seems like it could be a that of a Wheel Bearing, CV joint or the Front Differential. Now for the tricky part, the noise only occurs while accelerating and It doesn't matter if I am driving straight or turning (either direction). If I coast, the noise dissipates or disappears (it's hard to tell but its not audible). Which leads me to believe that its most likely the front differential. Does anyone know what is causing this noise?

I uploaded a video to YouTube (link below). The noise I am talking about is at the beginning of the video. At 0:08 I let off of the accelerator.

 

Thanks!

 

 

sounds like a wheel bearing to me.

next time you drive it - go feel the center of the wheel, if that side is notably hotter then it's the wheel bearing.

if you have one of the infrared temp guns, they are helpful for this too - hit various points on both hubs and compare temps. a really bad bearing will make one side hotter than the other.

 

vibrations would suggest axle, have any vibrations at all?

 

that doesn't sound like a front diff to me, they have more of a "grinding noise" in my experience, but maybe it's hard to hear on youtube?

did you check the front diff fluid?

Edited April 30, 201114 yr by grossgary

Front diffs whine.

 

Tis may the begings of wheel bearing failure, allowing just enough play to rub something or sideload the bearing. Jack up that tired and check for play. SPin the tire and listen for grinding noise

sounds like a wheel bearing to me.

next time you drive it - go feel the center of the wheel, if that side is notably hotter then it's the wheel bearing.

if you have one of the infrared temp guns, they are helpful for this too - hit various points on both hubs and compare temps. a really bad bearing will make one side hotter than the other.

 

vibrations would suggest axle, have any vibrations at all?

 

that doesn't sound like a front diff to me, they have more of a "grinding noise" in my experience, but maybe it's hard to hear on youtube?

did you check the front diff fluid?

 

I have a temp gun but I didn't use it because the hubs seemed to be the same temperature... cool. There are no noticeable vibrations. With the sound that its making it seems like it should be doing more vibrating. I have not checked the front diff fluid by draining it yet... only with the dip-stick and it doesn't smell burned.

Front diffs whine.

 

Tis may the begings of wheel bearing failure, allowing just enough play to rub something or sideload the bearing. Jack up that tired and check for play. SPin the tire and listen for grinding noise

 

I have jacked it up and checked for play, Nothing. I spun the tire and there is a little bit of a grind. Between the two of you it seems like wheel bearing is my best bet. They are cheap enough to just try it out to see if it fixes or rules it out haha.

 

now where did I leave that bearing press...

sounds like wheel bearing. some folks say turning it with a dowel rod or mechanics stethoscope on the strut springs helps amplify it a bit if you want to check some more..

 

i've seen a bunch of subaru wheel bearings fail that are perfectly tight with *zero* play in them until the entire hub is finally off the car. actually - i haven't seen one Subaru with a failed front wheel bearing that had any play at all - they were all tight as could be. once disassembled and laying in my garage now they have play.

 

i've seen play in the rears (but that one was also the worst one i've ever seen, throwing off the ABS, etc.

So, I removed the hub and pressed out the bearing to discover one wheel bearing fully intact with no flat spots or hang ups. I slapped it back together with fresh bearing. I then put it all back together and took it for a test drive. I am still trying to determine what it is. If not a wheel bearing then what could it be?

i started asking about axles and never followed up on that, my bad. if the axles have ever been replaced then that's a good chance of being the culprit. what's the history on the axles? the only sure solution for axles in my opinion is Subaru or MWE, everything else has a risk asociated with it.

 

if you wanted to test you could swap sides (right to left and left to right) and if the noise moves you'll know for sure it's the axle.

 

issues during acceleration are usually with the inner joint though, but aftermarket axles are junk so nothing would surprise me - i had one blow to pieces with less than 10 miles on it. i now only use Subaru or MWE axles.

I would have guessed axle and not bearing. When a bearing goes bad, it is more likely to make a steady grinding noise, not JUST on acceleration.

If it's just on acceleration, it sounds like the pinion in the front differential to me.

 

I recently swapped out the transmission in my Forester because it was making a bad whine in the front diff...bad pinion bearing, or pinion and ring gears, or both. Installed the new (used) whole transmission, and the sound was gone. The whine that the original transmission produced, at first, only happened during acceleration. As it got worse, it was audible at maintained highway speeds, then sub-highway, then anything above 12mph regardless of acceleration. The noise is always worse when accelerating, though. Let off the pedal, and the sound goes away.

Sorry I had to take a small vacation from trying to figure out what the noise was to go fishing.. haha anyway I'm back at it.

 

Gary, I think they are non Subaru CV shafts (as is third party) how could I tell for sure?

sweet, fishing is an excellent excuse to disappear. what did you catch?

 

not sure of a definitive way of telling subaru or not on the axles. you could post a picture, paying particular attention to the banding clamps - aftermarkets often have completely different style clamps.

sweet, fishing is an excellent excuse to disappear. what did you catch?

 

not sure of a definitive way of telling subaru or not on the axles. you could post a picture, paying particular attention to the banding clamps - aftermarkets often have completely different style clamps.

 

I caught (and released) some small to medium sized Large mouth Bass and Northern Pike.

 

Here is the picture... I'm guessing that the joint is Original with a replacement boot?

 

definitely not the CV axle... I swapped it out and the noise is still present. so next on the list is front differential?

Just wanted update everyone. The noise went away! all I did was swap out the transmission/transfer case both front CV Axles and replaced the front breaks. Problem Solved! Good luck to anyone trying pinpoint the problem haha.