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Zf4hp22 problems


bobtail ed

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Hello

Iv built a new buggy that a fitted an auto box in

iv built it from scratch after the 2nd gear box I now have drive because I think I aligned the torque converter correctly

But I took it for a test drive today and it seams to be stuck in top gear and struggles setting off.

from looking on the internet I think its the lack of kick down cable or lack of oil or just because its been sat for a while

if it because I don't have a kick down cable then does any one have a photo of how it fits on the carbs

or is it that I don't know a thing about autos

thanks for your time reading this ed

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The kick-down cable is important. More so on a mechanical than an electronically controlled box.

The box needs to know the throttle position as the gear is selected by the combination of the engine load (proportional to the throttle) and the road speed. With zero throttle, regardless of the speed, it thinks you are coasting and selects the highest gear possible.

It also changes the hydraulic pressure which affects how quickly / sharply it engages the gears. At low speeds / low throttle, the pressure is low and the gears engage softly giving smooth gear changes. The down side if this is the brake bands slip a little generating more heat, but as you are not putting a big load on the box, that isn't a problem. At high throttle, the gears engage sharply making it more responsive and generating less heat. This only tends to be an issue with electronically controlled boxes.

The adjustment of the cable is important because it maps the change points on the gearbox to the power curve of the engine. If you find it's forever changing gear when you are trying to keep a constant 30 or 50 for example, adjust the cable a little to move the change point up or down.

Si

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its simple enough to attach to carbs , usually run in parallel with throttle cable, need a bracket to hold outer, and the arc of operation should achieve full travel just after end of throttle arm travel. The kickdown should occur just before end of throttle cable travel, you feel it as a jump in cable . There is usually a seal set to stop inner cable dropping back too far , this is normally set about 1/4 inch before cable can go totally slack. This is a general set up method.

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