2001 Chevy Astro loud humming @approximately 75MPH behind d

2001 CHEVROLET ASTRO
76,000 MILES • 6 CYL • 2WD • MANUAL
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BDC960
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Our 2001 Astro has a LOUD humming behind dash @ about 75 MPH whether the AC or fan is on or off. It doesnt do it all the time and my wife said it did it @ 55 MPH a couple of times. I put it on jack stands to try and pinpoint the problem but the cruise wouldnt work with the wheels off of the ground. It doesnt do it all the time and when it starts humming it comes on all of the sudden and its LOUD. When you slow down to 65 or 70 it stops. any suggestions? Thanks, Brian Crawford @ [email protected]
Jul 21, 2009 at 7:01 AM
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RACEFAN966
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Ok there is a service bulletin on a loud humming noise. It is said that the final drive in the transmission can cause this. Bulletin number 06-07-30-006 issued feb 7th of 2006. Now it also says to check a few things. When the noise come up does it change pitch if you steer from one side or the other. If there is no change other then lifting off the throttle then I would take it to a good trany shop and have them listen to it and let them know of the service bulletin. Let me know how it goes.
Jul 21, 2009 at 9:14 AM