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F0355
South Africa
298 Posts |
Posted - 18/11/2006 : 07:19:36
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I have yet to hear consensus on the exact method employed to double de-clutch when asking around. No two tales of the method seem to mesh for me. Over the years I have 'figured out' my own method that works for me, but would like to hear from hardened MMM stalwarts the exact method used.
Thanks and regards,
Peter Steyn Johannesburg, RSA
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David Griffiths
United Kingdom
47 Posts |
Posted - 18/11/2006 : 22:24:47
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Peter
I quote from 'Car Driving as an Art' by S.C.H.Davis published in 1952!!
Lets consider changing from second gear to third gear The drill is: 1. Release throttle pedal - push clutch pedal down - gear lever into neutral - all simultaneously 2. Release clutch pedal - push throttle pedal part forward 3. Release throttle pedal - push down on clutch pedal - gear lever into third all simultaneously. You should now be in third gear. Note - The only difficult part is knowing how far to push down on the throttle pedal - you should push down on the throttle pedal until the engine is making the noise it would in that next gear, this is the bit that needs practise. Practise this on a stationary car - engine stopped - until it becomes a smooth rhythm - Then find a quiet road and practise this again at your own speed. Changing down the gears is the same procedure.
best wishes
David |
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F0355
South Africa
298 Posts |
Posted - 19/11/2006 : 07:43:23
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....you begin to see where I'm coming from ![](images/icon_smile_wink.gif)
Peter Steyn Johannesburg, RSA
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Alex
United Kingdom
48 Posts |
Posted - 19/11/2006 : 10:10:31
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The Davis book really does beggar belief. It's not an 'alternative method', just wrong (from a laws-of-physics point of view) and completely unhelpful.
In the M-type Manual, MG themselves give an alternative method of changing down when climbing a hill: don't touch the clutch, just keep your foot hard on the throttle while slotting the gearlever straight forward from 3rd to 2nd. The idea is that in the time it takes for the lever to pass through neutral between gears, the engine has revved up to the right speed! |
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John
United Kingdom
51 Posts |
Posted - 19/11/2006 : 10:40:14
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Just to add an extra aspect to the discussion, what is the basis of a "silent third gear box", and how do you use it to advantage? |
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George Eagle
United Kingdom
3240 Posts |
Posted - 19/11/2006 : 13:10:52
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I recall speaking to Steve Dear who was very successful when trialling his Cream Cracker PA and PB. If my memeory serves me right he just used to change gear without using the clutch! Very nice if you time it correctly but very noisy if you get it wrong. |
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bahnisch
Australia
674 Posts |
Posted - 20/11/2006 : 09:46:35
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Many years ago I could change up in my P-type by snapping the lever quickly and changing down I double-declutched and changed down almost equally quickly. My (current) M-type is similar. My F-type, however, is a different story. Changing up is no problem if you snap the lever very quickly with no double declutching. Changing down, particularly into second, is extremely difficult and double-declutching seems to make no difference. I have consulted the "experts" here in Oz and the concensus seems to be that changing down you just have to match the engine revs (not easy when the car is only used fairly infrequently!). I am inclined to think that that is one of the reasons that they went to preselectors when circuit (as opposed to places like Brooklands where you just got into top gear and held on!) began, bearing in mind that "manual" K3's, for example, ran the same ENV box! |
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LesG
United Kingdom
18 Posts |
Posted - 28/11/2006 : 18:07:57
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Just to answer the question of the silent third gear. First and second are straight cut gears which are noisy in operation but relatively cheap to produce; third gear is a double helical which is quiet when running but more expensive to produce. Top gear ,of course, is a straight through drive with the main shaft locked to the first motion shaft, so no gears of any kind to make a noise. Like most things our gearbox is a compromise of quality against cost. The third gear,which is 'floating' when not in use ( spinning free on its shafts), is locked to the layshaft and main shaft by 'dog clutches'when required. Trouble is these dog clutches need to be rotating at a synchronised speed to engage without crunching so we still need to double de-clutch!
Les Green |
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Bob Stringfield
United Kingdom
854 Posts |
Posted - 03/12/2006 : 21:41:24
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I was taught to drive, by my mother, an expert, on a car without synchromesh. After nearly half a century, with two unsynchronised mistresses, I can only state that, like some other activities, It needs affection between the participants, constant practice, but still doesn't work 100% every time. |
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mgmog
United Kingdom
467 Posts |
Posted - 03/12/2006 : 22:31:43
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roflmao |
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Peter Scott
United Kingdom
1240 Posts |
Posted - 03/12/2006 : 22:59:55
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..... not another acronym |
Edited by - Peter Scott on 03/12/2006 23:01:20 |
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Peter Scott
United Kingdom
1240 Posts |
Posted - 04/12/2006 : 18:52:16
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OK Richard, I have worked it out. Guess I have learned to understand your sense of humour.
Peter |
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