Dan,
Some of us learned to drive in a 49 4-speed pickup with no sycro's and
you have explained perfectly what happens and how to do it. Now, when
you double clutch you just push the clutch in to make it easier to slide
the tranny into netral and then you let the clutch out so that you can
control the speed of the gears with the speed of the engine and then when
you get the speed right you depress the clutch again to make it a little
easier to slide it back into gear. This knowledge and enough practice
will let you shift anything (I can do it on a John Deere tractor! ) with
or without synco's !!
Safety Fast.
Dwade
On Mon, 19 May 1997 DANMAS@aol.com wrote:
> Fellow Listers:
>
> Many years ago, I drove a large Mack dump truck for a living. At that time, I
> was not the giant of a man that I am now. I stood 5' 6", and weighed 112
> pounds (I'm still 5' 6", but I've added a few pounds. OK, a lot of pounds).
> In order to drive that beast, I had to learn to double clutch. Perhaps a
> brief description of what takes place during this manuever would be helpful
> for those new to it.
>
> When you are travelling along at a steady speed, or accelerating, the gears
> on the input shaft are DRIVING the gears on the output shaft. The teeth on
> the input gears are applying pressure to the output gear teeth. When you lift
> off the throttle, and use the engine to slow the car, the gears on the input
> shaft are now being DRIVEN by the gears on the output shaft. Now, the teeth
> on the output gears are applying pressure to the teeth on the input gears.
> During the transition between these two conditions, there is a period at
> which no pressure is being aplied by or to either set of gears, and they are
> rotating at the same speed. At this time, only the slightest force is
> required to slip the transmission into neutral.
>
> Once in neutral, the output shaft continues to rotate at the same speed as
> before (at least until the car slows down). The input shaft is rotating at
> engine speed. If you now rev the engine up to where the engine RPM nearly
> matches the RPM it *WOULD BE* turning if it were in already in the lower
> gear, the two shafts will now be turning at almost the same speed. Since they
> are turning at the nearly the same speed, there would be very minimal
> pressure applied to the gear teeth if the gears were to be meshed again.
> Since it is impossible to exactly match the speeds, if you lightly press the
> gearshift lever, the two gears will rotate till the teeth are in mesh, and
> the transmission will readily slip into gear with no damage.
>
> Of course, shifting up is the reverse of the above. You let the engine speed
> drop till it matches the speed it will be at when in the higher gear.
>
> With a little practice, except for starting from a stop, the clutch becomes
> redundant. I don't recommend this method, but if you are having clutch
> problems, or transmission problems, it can be a lifesaver. Combining this
> technique, with the use of the clutch, significantly reduces the strain on
> drive train components.
>
> Given my druthers, I'd druther drive an LBC!
>
> Dan Masters,
> Alcoa, TN
>
> '71 TR6---------3000mile/year driver, fully restored
> '71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
> www.sky.net/~boballen/mg/Masters/
> '74 MGBGT---3000mile/year driver, original condition
> '68 MGBGT---organ donor for the '74
>
>
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