Hugh and others,
I think a minor clarification is in order to what Randall has said. He's
correct with regard to the rotation of gears in neutral if the car is at
rest, however if coasting with the gearbox in neutral the mainshaft is then
driven by the differential. The syncro assemblies are spinning. If you were
to engage a gear but not engage the clutch then the gears in the
transmission would be being driven but by the differential not the engine.
It's a very minor point but it would tend to load the transmission gears
differently and perhaps provide additional clues however minor they might
be.
For what it's worth my 1966 TR 4A which I have owned since 1969 has always
had what I considered a gear whine when accelerating in fourth gear. I've
changed differentials and ratios and it's still there so my conclusion was
that what I hear is normal. Also, after I changed from the old worn out
fiberboard tunnel cover to one of the "SpaceAge" plastic covers I sure heard
a lot more gearbox noises, especially when in O/D. It's a long shot but have
you changed covers and now hear more noise? That fiberboard was a much
better sound deadener than the space age stuff. Come to think of it there
was some recent chatter about fitting a plastic cover and having to elongate
some of the holes, was that you Hugh; who posted those messages?
Jerry Van Vlack
----- Original Message -----
From: "Hugh Fader" <hfader@usa.net>
To: "'Randall Young'" <ryoung@navcomtech.com>
Cc: "'triumphs'" <triumphs@autox.team.net>
Sent: Saturday, September 14, 2002 8:06 AM
Subject: RE: Whine in gearbox or differential?
> Hi Randall. Thanks for responding.
>
> >
> > > Another question: Since the main shaft speed also varies
> > with road speed,
> > > couldn't my noise be coming from it's gears?
> >
> > With the gearbox in neutral, there are no gears that turn at
> > output shaft
> > speed. All the transmission gears (except reverse) are
> > driven by the input
> > shaft all the time, the gear shift just picks which one is
> > locked to the
> > output shaft.
>
> Yup. I understand that part. I only get a sound when in gear or a more
faint
> sound just as I begin to shift. I get the same pitch no matter which gear
is
> engaged. As Dave said this points to the differential. I guess I'll verify
> this with the car up on stands.
>
> >
> > Running it up on jackstands isn't as scary as it sounds.
> > Just be sure you
> > have the stands with the cast jaws and welded body. The
> > stamped sheet metal
> > ones aren't safe IMO.
>
> Pretty sure mine are as you describe. I'll take a good look to make sure.
>
> Thanks,
> Hugh
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