Purpose of the throttle switch is to save wear and tear on the overdrive and
driveline. When you kick get out of overdrive the motor will need to be
going faster to match road speed. By requiring a certain degree of throttle
before this happens you should get less of a clunk when you shift out of OD.
It is probably uneccessary, Triumphs and many other cars did fine without
the extra bits, but it is the way they were built, I kind of enjoy mine. If
you know a stop is coming up you can switch out of OD, take your foot off
the gas to slow down, and then when going slower give a little throttle to
kick out of OD. I don't really like the feature when a stop comes up
suddenly or unexpectedly, because I still want to kick it out of OD before I
slow down.
Greg Lemon
54 BN1
----- Original Message -----
From: "Alan Schultz" <alan@andysnet.net>
To: "Bob Spidell" <bspidell@pacbell.net>
Cc: <healeys@autox.team.net>
Sent: Saturday, November 06, 2004 3:16 PM
Subject: Re: Overdrive wierdness - I'm not really sure
> Bob,
>
> Thanks for the lesson in technique.Hope when I blip the throttle at the
> stop light some hot rodder isn't considering it a challenge. I see
> little reason to keep the throttle switch. If I plan to pass someone I
> could just flip the switch to normal. Seems its the only reason for the
> switch?
>
> Bought my 53 BJ8 from a guy living in Madison, WI who had taken it
> completely apart years ago. It was a "basketcase" or should I say "boxes
> and bags case".
>
> Bob Spidell wrote:
>
> > This should probably be re-subjected to "O/D Technique," I suppose.
> >
> > Anyway, my O/D tecnhique is a follows:
> >
> > a) on "upshift" (from straight 3rd or 4th to 3rd-O/D or 4th-O/D) I just
> > flip the fascia switch at or near WOT. The result is very similar
> > to an automatic transmission upshifting
> >
> > b) for "downshift" (from 3rd-O/D or 4th-O/D to straight 3rd or 4th) I
> > push the clutch in a little (inch or two), rev the engine a little
> > and throw the
> > switch. If done just right, this results in an almost
> > imperceptible downshift;
> > the only effect is an increase in engine speed.
> >
> > I have 140K+ original miles on my O/D, and I've gotten 80K miles--and
> > counting--on
> > my latest clutch so I think this technique is fairly friendly to the
> > machinery.
> >
> > Alan: yes, that's normal for an O/D. The throttle switch will keep
> > the O/D
> > engaged until the throttle is opened something like 3/16" measured at
the
> > stops (probably around 1,500 - 2,000 RPM). BTW, you didn't get your
> > "53BJ8" off of eBay by any chance? ;)
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