LopeyZ

iTrader: (2)

So I picked up a 2002 WS6 yesterday with 120,000 miles on it as a car to mess around with on the weekends. My buddy and I who have both owned LT1 cars in the past thought this car had an unusal amount of road noise. The owner said the tires were newer but they are some off brand that I had never heard of and can't even remember the name right now. He said they got bad ratings but they were cheap and so was he. The sound is really similar to going from smooth pavement to really rough pavement on the highway only this car sounds like rough pavement the entire time on the highway. Now I thought about it last night and noticed it had a pinion leak but haven't have had a chance yet to check the fluid level.. will do that this afternoon. So that got me thinking maybe it's gear noise (though not a whine) or possibly bad bearings. Aside from changing gear lube, I have never broke into a rear diff before so I'm a little unsure of how to test a bearing. I thought about simply jacking up the rear diff so the suspension has load and pinion angle is the same as on the street and then running it stationary up to maybe 50 mph. I want to see if I can simulate the cabin noise on the highway with this method. My only concern (aside from falling off the jack and ending up in the neighbors kitchen) is that without load on the drivetrain, the noise may not occur. I am really hoping it's just crappy tires but if I need to replace bearings then I'd like a decent method of testing them first. The wife would get pretty annoyed if I was tearing into the car a week after owning it without showing her evidence of a problem LOL... women never understand. Sorry for the long post!

DNTBJELOUS

iTrader: (2)

I was seriously just about to post the same issue. Have you tried possibly rotating your tires yet? I ended up throwing new tires on the back & still had the same noise your describing. I also have a pinion seal leak. I believe it is the bearings in the axles except who knows? When replacing my rear diff cover I inspected all my gears & everything seemed to be in order. No major play & the teeth all had normal wear. Barely anything if any metal debris/shavings when I pulled the cover off as well. Only other thing it could be I guess is the bearings except I just have not gotten around to replacing them. That is on my to do list though very soon. I was snooping around online last night really quickly trying to find some, but had no luck. While I'm in there I figured I'd also just put new axles in as well. Does anyone know if any manufacturers include the bearings with the purchase of axles?

FirstYrLS1Z

iTrader: (4)

On the GM 7.5/7.625 rears,axle bearings/seals are part of the housing,not part of the axle as on some larger rears.

LopeyZ

iTrader: (2)

I didn't get around to checking the fluid level but the tires are Nexen N3000 and while cheap, guys aren't giving them terrible reviews. I have been doing some research on here and many guys have said they just take the bearings to a shop and have them install new bearing and races. As long as the same shims are used, there should be a need to check gear lash but I dunno... sounds risky. Maybe I can find a low mileage rearend.