adwinistrator Posted January 4, 2016 Share Posted January 4, 2016 Backstory Transmission was rebuilt at 86,000 miles 3 years ago (lost 5th gear). Sold to previous owner at 110,000 miles, I purchased at 125,000 miles 6 months ago. I had the transmission fluid changed at the beginning on December. Here's a picture of the fluid that came out. A few weeks later, I heard some speed related scraping noises that went away after a few minutes. My first thought was wheel bearing. On 12/26, I start hearing a whining noise, like a wheel bearing would make. It changes pitch and intensity as wheel speed increases, no changes on acceleration, deceleration, steering, gear change, or neutral. I was hoping it was a wheel bearing, but the fact that it didn't change when steering had me concerned. [ame=www.youtube.com/watch?v=br9iXvEXRkk]Drivetrain noise[/ame] In the following days, the noise would come back after about 10-15 minutes of driving. Took the car into my shop on 12/31 and had them check it out, the sound is coming from the center differential. On the way there, the noise didn't seem to come back while I was on the thruway, but when I got on the side roads, I could hear it again. The range and pitch of the noise/speed seems to have changed. Diagnosing I'm not sure exactly what is causing this noise. My main guess is the rear bearing on the transfer driver gear (output shaft) of the center differential. A lot of the people with center diff noise say that the noise is only during acceleration or deceleration, but that's not what my problem is. Decision Time They recommended that I purchase a used transmission and swap it out. Their rationale is that it's highly unlikely that one bearing is the only issue with the transmission, and that doing the service might end up being a waste of money. I've been doing a bit of research online, and this seems like a somewhat common issue. People are writing up DIY center differential bearing replacement guides. LegacyGT.com guide NASIOC thread The only used transmission in the area would cost $1,400, free delivery, 30 day warranty (parts only), and has 114,000 miles. Labor would be about $650. If it's just the center differential bearings, parts would be about $175, labor about $400. If the differential's viscous coupling is damaged, the cost would end up around $1,100. To just open the center differential and see what it looks like would be about $250. I'm leaning towards having the shop open up the differential and proceed from there. If it looks like there are worse problems then just the bearings, I'll purchase the local transmission, or order one with less miles and pay shipping, then have them install it. Questions What would you do if you were in my shoes? With the noise being consistent with the wheel speed, and not changing depending on other factors, would that lead you to believe that it's the differential bearings, or the differential's viscous coupling? I would think if there's noise on load, that it's the viscous coupling, whereas if the noise happens all the time, it's a bearing. Thanks in advance for any advice you can give! Link to comment Share on other sites More sharing options...
ssulb Posted February 9, 2016 Share Posted February 9, 2016 This happened to my 2001 Forester at 250,000 miles but mainly because of differential oil change neglect (not my fault). At first it sounded like a bearing and then over time the sound got worse, from metal grinding to loud metal knocking. The amount of sound and frequency did change according to the speed of the car. Then when I was driving home the front differential finally gave out. I made it home (not far away) trying to force the Subaru to spin the rear wheels only. Sometimes it would feel like it was just trying to spin the front wheels. Later on I replaced the entire transmission with a lower millage one. I asked the dealership they said it those were the actual differential bearings that made that noise. But that's my little story. The winning noise seems to be coming back though on the newer transmission. Fresh oil though. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
channoff Posted March 29, 2016 Share Posted March 29, 2016 Doesn't look like you got much help on this. There are many threads on this bearing issue. Here's my 2 cents... Buy the bearings an just do it yourself. I did my bearings last year and it is fairly easy, albeit a little time consuming. Took me about 4 hours but I think I could cut that in half now. There is a really good walk through somewhere on forum. Worst case scenario you spent $175 extra and it didn't fix the problem. That is less than 10% more than used transmission cost and installation. Link to comment Share on other sites More sharing options...
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