On 16 Sep 2005 21:19:02 -0700, "John Manner" posted that:
: :: :::> Driving from 30mph to highway speeds I can hear a slight humming from : :: :::> the front end along with vibration sometimes in the floorboard. It : :: :::> isn't loud or anything, I just know it is there and that it is a new : :: :::> sound. After looking at posts for awhile, I have seen suggestions that : :: :::> the differential is engaged to bad wheel bearings. I can say that it is : :: :::> quiet at low speeds. What do you guys suggest I look at first? : :: :::> : :: :::> Thanks, : :: :::> John Manner : :: :::> 1999 Blazer 4.3L 4x4 (AutoTrac) : :: :::> 97,000 miles
This happened on my 98 Blazer, and driving into a strong wind really made it sing. Turned out to be the aluminum skid plate under the transfer case. It's mounted using shoulder bolts and spring washers that was worn out allowing the plate to viberate. I replaced the rusty spring washers with stiff rubber washers and the problem went away. This setup is supposed to let the plate move.
BTW, I have the ZR2 package and don't know if this skid plate is on all the trucks.
LockJaw