Chris Prugh wrote:
> I have : 1. Replaced the u-joint on the diff end of the prop
> shaft (trans end is the newer cv joint style)
> 2. Had the prop shaft balanced.
> 3. Had the axle shafts/hubs rebuilt.
> 4. New uj's on axle shafts.
> 5. New 3.89 rear end.
> 6. New bushings thoughout the rear end suspension.
> AND STILL...the MOST annoying click sound is still present.
> Who knows what the diagnosis procedure should be at this point?
I have had similar annoying clicks from my TR6. I have found the most
valuable diagnosis tool to be to reproduce the sound with the car in the
garage. But, before trying that, the most important question to figure
out is *when* the sound occurs.
First, when does the sound occur? All the time that the car is
moving? Only when applying power? Only when lifting off the gas?
When applying power or lifting off the gas? When going over bumps?
Only when first letting the clutch out? Only in certain gears?
Only at certain speeds? (You get the idea by now, I reckon...)
Depending on when you get the sound, you then need to try to reproduce
the sound with the car in the garage, and the engine off. If the
sound occurs when first applying or removing power you can probably
reproduce the sound by putting the car up on jackstands (make sure it
is rock-solid on the stands!), placing the car in neutral, and then
sharply rotating and stopping one of the rear wheels by grabbing the
tire at top and bottom, using both hands, and then "jolting" the tire
into either forwards or backwards rotation, and stopping it equally
abruptly. The intent here isn't to spin the tire as fast as you can,
but to apply the largest possible "jolt" to the drivetrain. Don't
be afraid to hurt it! By starting/stopping the wheel with your hands
in this fashion, you can't possibly apply anywhere near the jolt that
the drivetrain gets even on a moderately smooth application of the
clutch. If you can reproduce the sound in this way, teach an assistant
(spouse, friend, neighbor, child) to make the same sound happen. Then,
once they can make the noise happen, get under the car to watch and
listen while they make the sound. You'll be able to localize the
sound very well, and will probably actually be able to *see* what it
is that's causing the noise. Don't just look at the moving components,
it could be differential mounts, suspension mounts, shock absorber
mounts, transmission mounts, and other similar connections that have
play and are causing the offending "click."
If you can't reproduce the sound with the above, try having the
assistant hold the opposite rear wheel from turning, while you repeat
the jolts on the rear wheel. If that still doesn't work, put the
transmission in gear (you'll need to let the opposite wheel spin for
this to work.)
If the problem only occurs during continual rotation, spin one, or
both wheels in this fashion. Once you can make the sound, it will
be easy to localize it.
If the sound occurs when going over bumps, try to make the sound
happen by "bouncing" the car. (Oh, the car should be on the floor,
NOT jackstands at this point... :-)) If this makes the sound (and
yes, you'll recognize it when you hear it!) then have your assistant
bounce the car, while you look/listen to see what is making the
noise.
If none of the above produce the sound, it may be that the car
only occurs when the wheels are rotating, and the car's weight is
on the suspension. In this case, try to reproduce the sound
while driving slowly in your driveway (or a parking lot). Then,
have your assistant drive the car to make the noise, while you
stand nearby. This will help a lot in localizing the sound.
Be aware that the apparent location of the sound can be quite
distant from the actual source when in the passenger compartment
of the car.
You don't have to be resigned to live with it -- but you may need
to be really persistent, and creative in order to find the sound!
--ken
VTR WWW Maintainer -- http://www.vtr.org
'74 TR6 6-month Daily Driver, which currently makes a similar sound,
from a broken diff mount...
--
Kenneth B. Streeter | EMAIL: streeter@sanders.com
Sanders, PTP2-A001 |
PO Box 868 | Voice: (603) 885-9604
Nashua, NH 03061 | Fax: (603) 885-0631
|