Possibly a bad wheel bearing?

[astron]

Okay...i've got quite possibly the strangest noise in my 240sx...at cruising speed, 45+, i get what i can best describe as a sanding sound...it's not constant, it happens mostly when going down hills or over bumps...I'm fairly sure it comes from the rear drivers side. It's been suggested that i check the diff oil..which i'm not real sure how to do, but i've got a shop manual so i'll figure it out...Btw, new brake rotors and pads didnt fix it, or if they did it came back very quickly...any ideas?thanksast

[IveBeenBad]

Dont check the diff fluid, change it. Undo bottom (drain) plug, let fluid drain, close plug, open top plug, syphon gear oil in.

How many miles are on the chassis?

[astron]

Okay, will do..was planning on changing it afterward anyway, and it's at 95k right now...where's the top plug? I havent looked with the car off the ground, but i couldnt see it when it was on the ground...thanksast

[IveBeenBad]

if i remember correctly, its on the driveshaft side of the diff

[navysnail]

on the back of it, like half way up. use a 1/2 inch drive ratchet to get it loose. dont use a socket, just the end of the ratchet.

[89240sxdude]

if its the wheel berings it would probly make the noise when cornering or while going straight and stop making it when cornering

[astron]

you think so? hrm...it's pretty well the opposite actually, i think...like i say, it's not really linked to anything in particular...anyway, changing the oil should tell me if there's a problem (shavings) i'd think, and i'm sure the car needs it...thanksast

[astron]

Okay, got the diff oil changed. Figured for 20 bucks the decreased risk of me screwing it was worth it. There were apparently some very small metal shavings on the filler plug, the mech said it wasnt to worry about, but the fluid was alittle low. I'll see if the noise is gone when i drive again tommorow...Kinda hard to find highway around here