'02 Bravada- acceleration NOISE!

[wrong83]

Hey everyone I just recently replaced my fan clutch. When the fan started sounding like a jet engine I also noticed another noise that initally sounded like it was coming from inside the rear part of the car. After I rolled down the windows and listened to it, it sounds like it's coming from under the car. I only hear the noise when I'm accelerating in gear. The noise changes tones and frequencies while I'm driving, it's quite wierd. After I got the fan clutch replaced I figured the noise would go away but it did NOT. Has anyone else experienced a noise which I can best describe as a whining one, but again the noise changes periodically. It doesn't sound like it's coming from the engine, it sounds like it's in the muffler almost. Thanks!

[Chris Stewart]

I've had transmissions that whined. How many miles do you have on your Bravada?

[ericn1300]

could also be the rear differential, check the fluid level. once you get a whine there you can replace the cover gasket and fluid and live with it but a rebuild is the only way to get rid of it. also check the u-joints

[wrong83]

There's 77,000 miles on it, is it normally to hear different whine tones and such from it the rear differential. If I give it gas and then let off of it and it cruises for several seconds it sometimes goes away even if I'm cruising at 20 mph.

[ericn1300]

Originally Posted by wrong83

There's 77,000 miles on it, is it normally to hear different whine tones and such from it the rear differential. If I give it gas and then let off of it and it cruises for several seconds it sometimes goes away even if I'm cruising at 20 mph.

the back lash in the gears becomes greater as they wear and the surfaces get damaged if you run low or out of oil. the gears are biased in one direction when accelerating and the opposite when de-accelerating which cause different noises.

[wrong83]

The noise hasn't really increased in sound, it's the same noise level as a week ago. I'm still questioning whether the oil level is low and it's the differential that's causing the noise.Thanks for your help. I'm going to take it in and have them check the differential box.

Originally Posted by ericn1300

the back lash in the gears becomes greater as they wear and the surfaces get damaged if you run low or out of oil. the gears are biased in one direction when accelerating and the opposite when de-accelerating which cause different noises.