Gearbox shift point

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morgan
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Gearbox shift point

Post by morgan »

Just a quicky - more for my own learning really.
My gearbox is a 727, works nice, leak free (woohoo!). Kickdown OK, but needs near full throttle.

I'd like it to hold the gears longer (not upshift to top at 20) and kickdown at (say) 50% throttle rather than 90% throttle.

Is it just a case of adjusting the linkage to pull the lever sooner ? Will that make it hold gears ? As far as I can see its a bit of a dark art of compromise. I can find threads of people saying their car doesnt shift to 3rd until 60 !

PS - Its a lokar, so 1:1 relationship, cant adjust ratio on a cam like the boillion/boucillon/boolion
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Pete
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Re: Gearbox shift point

Post by Pete »

Have you got the kickdown adjusted correctly?

Failing that it may be the Governer....
Pete Wiseman; Cambridge.

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morgan
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Re: Gearbox shift point

Post by morgan »

That's kinda the crux of my question I think. "Can I control a) When it changes up and b) when it kicksdown - just by adjusting the mechanism ?"

Its in the ballpark, car drives fine. I dont think I have a problem - I'd just like it to hold the revs a little longer and kickdown without KICKDOWN-WaaaaAAAHHHHH. Its not a problem, just trying to expand my learning.

(The governor (as I understand it) chooses when to say 'easy tiger, enough' and change up at the top. This is fine also - no known issues)

Just fettling...
"Cum homine de cane debeo congredi." Woof.

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Pete
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Re: Gearbox shift point

Post by Pete »

You should not "Play" with the kick-down mechanism - it directly affects line pressure so adjust it correctly.

Stick a manual Valve body in it - you will never look back!!!
Pete Wiseman; Cambridge.

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Blue
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Re: Gearbox shift point

Post by Blue »

Yes you can play around a bit with the adjustment, and yes within reason you can alter the shift points. The base setting is kickdown lever fully back at full throttle. Lengthening the the Rod at the carb from that setting slightly will raise the part throttle upshift, and it will kickdown at a bit less than full throttle. Basically, the further back the kickdown lever is for a given throttle opening, the later and firmer it will shift, and vice versa. Don't forget though with a rod linkage, once the kickdown lever is all the way back it won't allow the throttle to open any further so it's a balancing act.
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morgan
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Re: Gearbox shift point

Post by morgan »

Much obliged chaps.
"Cum homine de cane debeo congredi." Woof.

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