Hi all.
I've been a happy owner of a 01/2003 LS430 since 2016. She's on her 210k mile these days. All services have been kept current (including bigger ones like suspension and wheel bearings). About a year ago I started hearing a humming sound from the back of the car. Thought it was a wheel bearing (cause that's what it usually is in 99% of cases ). We figured out all 4 wheel bearings need replacement and we did replace them. Humming still there, but now the car drove way quieter haha. Anyway, I got so sick of it that I asked them to change the oil for the diff. When they did so, the tech mentioned there was a lot of shavings in the oil. Some is normal (like with any diff), but this was sparkly beyond normal. I drove the car for a while and the humming got worse. Got an ebay diff with 120k miles and swapped it in. The shop took it apart the old one and confirmed the diff was damaged beyond rebuilding. But the noise was GONE. Rejoice! Case closed!

Not really. The sound is back after 3 months. So I'm certain it's the diff, but I'm thinking about my options - I don't want to go and buy another mystery diff again to repeat what I've just done. Are there rebuild kits? Are there people who rebuild them (properly) and take core charges? I'm not sure what to do at this point. I've been searching for possible solutions (kits, diys, rebuilt diffs), but all I find is used ones on ebay

 

Curious to know, is there a LSD diff that we can drop in?

 

Did they check the bushings on the drive shaft to make sure it's not flopping around at weird angles damaging the bearings? Is there any loose slop in the drive train?

 

I'm not sure if they did, are you refering to the main driveshaft bearing or the guibos? or both? Might have those checked too. I'm curious as to how that would affect the diff so much it would grenade itself in a few thousand miles

 

Yes, supra or 2GS diff will bolt in. You can get an LSD from a BRZ for cheap now and supposedly the center section is the same

 

I'm assuming there's not much info on this problem? Could another part affect the diff so much that it would wear itself out? I've never seen that happen on other cars.