When my car was stock I had a problem with the rear differential making a whistling noise when I did 65 mph and then released my foot from the gas. The sound would stop at about 60 mph. Subaru replaced the rear diff. free of course....well now I have a turbo back exhaust and the problem is back (note that the problem did not come back after the exhaust was installed it has been several thousand miles since installation). I don't think the exhaust caused the differential to go bad again because the parts are not even related to each other. I took my car back to the dealership and they said that they didn't hear the noise which is b/s and they complained about the exhaust and that it voided my warranty.

First, what causes a differential to go bad?
Second, does a turbo back exhaust have anything to do with my differential going bad as well as being covered under my warranty?

I thought they were two separate things.......like if a part was to break on my suspension the exhaust would have nothing to do with my suspension, thus the suspension part would be covered under warranty.

I am taking my car back this Wednesday so any information would be helpful on what to say or do because I don't want the Tech to tell me something and I have no choice, but to believe him because I don't know about warranty or what makes this part go bad.

Thanks,
Chip

 

A TBE won't cause a diff to go bad, but if they want to be real pains in the asses they could try and claim that the additional power caused it to fail. Just familiarize yourself with the Magnusson Moss Act.

 

Howdy subie nation,
Just a line regarding warranty work. I have so far on my 04 sti had the rear struts, O2 sensor, major tranny work, window rubber replacement and coming soon probably a new rack and pinion (major shudder in tight left turns) and so far all of my work has been covered under warranty. I have swaybars, brakes and antilift kit and by the service tech guys they say that they would have to prove that the mods caused the failure and so far no problems, everything has been good. good luck with the warranty claims but so far my experience has been very good.

 

Well my I took my car to the dealer today and they were still kinda stuck on the exhaust mod, however the guy printed out something on the computer about the differential cross member, dampeners and a locking nut. It totally described the sound my car makes to a T. It said something along the line of that it makes a Hooing sound at a peak of 63 mph while accelerating or decelertaing. This happend on WRX's produced before April 04 and the cross member will be marked with an "E" if it is after this date the member will have a "D" Fortunately mine has an "E" so the tech ordered me a new differential cross memeber, dampeners, and locking nut. So hopefully this will fix the hoooing sound my car makes. Just figured I would let everyone know incase this has happened to anyone else.