Silverado Suspension Rattle
Q: My 2003 Silverado 1500 4x4 has a rattle coming from the truck's suspension on slight bumps. It sounds as if something is loose, like a metal-on-metal rattle. You can't hear it with the windows up or the radio turned up. I've been under there multiple times and can't seem to find anything that would cause the noise.
A: Your rattle can be hiding out in a whole bunch of places. It's always smart to inspect the entire suspension for any loose or worn parts and put a wrench on every bolt to confirm they're all tight. Even jouncing the truck up and down or banging on components one by one with a rubber mallet can help track it down. And a technician with the proper tools would have the advantage of utilizing an electronic listening device to zero in on the noise. But there are two particular areas of note. One is the lower insulators (round rubber bushings) on the top of the front shock absorbers. These insulators are centered on the shocks by plastic pilot rings. The rings have been known to wear out prematurely, misaligning the insulators and causing squeaks and/or rattles from the front suspension. You can avoid buying all-new shocks by replacing the insulators with modified part number 15834275--double-check with Chevy parts. Also check the stabilizer links that attach the stabilizer bar to the lower control arms. They're simply long bolts, with four bushings that look just like the shock insulators. They may be worn and loose. There are also cases where they haven't been torqued sufficiently and need only be tightened up.
RearView Explorer Vibration
Q: I own a 2005 Ford Explorer with a vibration problem that shows up on the left-side mirror at speeds between 55 and 70 mph. The inside mirror and right-side mirrors don't vibrate. I called Ford and the person I talked to called my dealer, who informed me it wasn't within their parameters. I disagree. The mirrors, right or left, should not vibrate at any speed. They also said it was due to aerodynamics, which is hogwash since all the mirrors have a shroud to prevent this.
A: I've run across similar situations with different vehicles, and each time replacement of the entire mirror assembly corrected the problem. For some reason, the fixture that held the mirror glass to the power mirror motor wasn't secure enough, allowing the mirror to jiggle or vibrate while driving at certain speeds. Ask the service-department personnel to take you for a ride in a similar Explorer at the same speeds at which you've experienced the problem. If the test vehicle's driver-side mirror doesn't vibrate, there goes the theory of a normal characteristic due to aerodynamics. If the test Explorer's mirror does the same thing, then maybe they're on to something, or maybe there's a bad batch of left-side Explorer mirrors out there. Other conditions that may amplify a mirror vibration are the mirror assembly not securely fastened to the door, the mirror assembly or door being bent/damaged and affecting aerodynamic profile, the door itself not secure or misaligned, or an unwanted chassis or driveline vibration, which you probably would've already felt in the steering wheel or seat of your pants. If you're still covered under the bumper-to-bumper warranty, I'm surprised the service department didn't replace the mirror in the first place.