Andrew Duane USG/PE wrote:
> Hairy green toads from Mars made Jack Rich say:
> > When I corner in my 84 4kq to the left, there is a steady
> > thump-thump-thump sound, whose rapidity is proportional to my speed.
> > When I go straight or turn right, there is no unusual sound. This
> > sounds like a wheel bearing about to go (right?) and it must be on the
> > right side of the car where the cornering forces are highest (right?),
> > but I can't tell if it's the front or the rear. I also am not sure if
> > a wheel bearing makes a thump once per tire revolution vs. a steady
> > rumble.
> It's a CV joint, not a wheel bearing.
> I forget which turn makes which side thump.
> Andrew L. Duane (JOT-7) firstname.lastname@example.org
> Digital Equipment Corporation (603)-881-1294
> 110 Spit Brook Road
> M/S ZKO3-3/U14
> Nashua, NH 03062-2698
> Only my cat shares my opinions, and she's too heavy to care.
>From my experience, wheel bearings moan on these cars when they're worn
out. You can hear it is a low, rumbling-grinding-type vibration that
occurs on one side of the car only and gets louder in turns opposite the
affected side of the car. Unless it is seized, but then I can't imagine
you going very far on a seized bearing. The CV joint suggestion is a
good one. Turn the wheel full lock at a standstill and then drive in
that direction. Maybe with an assistant you can hear from which side of
the car it is coming. Also, two other, outside chance things:
1: The brake shield has been dented or hit by something in the road and
has been brought sufficiently close to the rotor to intermittently
contact it when that wheel is loaded. Of course, this would sound more
like a glancing grind than a thump. The kind of runout/rust on the rotor
that could lead to this sort of sound should tell you to replace the
rotor and watch the wheel bearing if this is true, because there's play
somewhere, but it happened to me. The outermost diameters of the front
disk rotors on my car were not in contact with the pads, and consequently
rusted and developed strange protrusions over time, which caused this
problem when I hit a rock. BTW, I just bought a set of Brembo vented
front rotors for my '84 4KQ from Rapid Parts and they are superbly
manufactured units that I am now using to replace the CrudCo replacement
rotors that the previous owner slapped onto the car.
2: Is it a low, damped thump, thump? (more like a bhump, bhump?) (Ok, I'm
a weirdo). If so, check the tire again by spinning and eyeing it
carefully for an egg somewhere along the tread and both sidewalls.