Hello Everyone:
Here's a tech tip I stumbled upon in my attempts to get rid of a
horrendous "grinding and rattling" noise that developed around my Series
V Alpine's transmission tunnel area (except the noise was so loud you
couldn't really tell where it came from) above 4200 RPM.
I've owned a Tiger in the past that developed weird grinding noises too
so this may apply to both lines, although not necessarily the specific
fix.
It was suggested that I try greasing below the shifter as the parts
there wear and tolerences get bigger. This I did, but without an
improvement. Then I noticed that some noise seemed to be coming from my
shift knob. It's an aftermarket wood knob with the multi-color
Rootes/Alpine emblem on it that's commonly available. This knob turns
out to be hollow inside so it acts as a mini echo chamber and seems like
it can amplify whatever noises it picks up. I took the knob off and
filled it up with silicone seal (make sure you let it dry and scrape the
seal off the inside threads so you can still take the knob on and off
easily). This helped a bit, but not much.
Then, the master mechanic that I am, I noticed the insulation rubber on
the transmission tunnel was coming off in a few places. I peeled it back
further, revealing three metal "cover plates" on the trans. tunnel.
Almost all the screws were a bit loose to one extent or the other on all
of the plates. After tightening down all the screws, and filling a 1/2"
hole on the trans tunnel that at one time must have had a grommet on it
(just in front of the ash tray), a test drive revealed that all the
noises were gone! One of those plates must have started vibrating at
4200 RPM. It's amazing that such a small gap, which couldn't have been
more than a fraction of an inch, between one of the plates and the
trans. tunnel could have caused such a multi-decibel ear spltting noise,
through the insulation and the carpeting yet, but it did.
The moral of the story: Tighten down those screws.
Steve Sage
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