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ZF 2-3 shift on light throttle


darcati
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Need to pick the forum members brains on a ZF issue i have with my built ZF.

When it does the 2-3 shift in drive on light throttle at around 2000rpm it lets go of 2nd revs rise briefly before 3rd comes on rather than being quick and smooth.

It feels like the delay between 2nd letting go 3rd engaging is too long BUT changes below 1500rpm and above 3000rpm are fine.

Being new to this I'm not sure if I should I be adjusting off/on going pressures and where would these changes be done?

Appreciate any help in advance.

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On 1/28/2019 at 2:35 PM, darcati said:

Need to pick the forum members brains on a ZF issue i have with my built ZF.

When it does the 2-3 shift in drive on light throttle at around 2000rpm it lets go of 2nd revs rise briefly before 3rd comes on rather than being quick and smooth.

It feels like the delay between 2nd letting go 3rd engaging is too long BUT changes below 1500rpm and above 3000rpm are fine.

Being new to this I'm not sure if I should I be adjusting off/on going pressures and where would these changes be done?

Appreciate any help in advance.

Provided your transmission settings are standard copy the torque converter settings (yes torque converter settings) from a standard sprint tune and try that, it helped mine.

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  • 3 years later...

Post up a tune and log man, I'm keen to try and help out. Still learning the ZF's so may end up being hopeless to you. Presume box is in good nick? Give us a bit of info of what's been done. 

Create a new log layout with just the following channels. Less channels to make it log fast as possible. 

RPM
Throttle Position
Current Transmission Gear
ID Of Used Shift Pattern
Difference speed to synchronous speed
Nominal value TCC speed difference (value)
Pressure, on-coming clutch
Transmission Input Shaft (Turbine) Speed 
Nominal value of the CRC slip time
Pressure, off-going clutch
Shift Pattern Throttle Input Value
Transmission Oil Temperature
TCC Pressure
Flywheel Torque
Transmission Output Shaft Speed
Current Line Pressure
 
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It’s an fg na+t,the problem only started after the tune I got,it was doing it in all shifts but I upped the shit pressures 25% and it solved the problem in all other shifts besides the 2-3. it shifts out of 2nd firm and then is like someone very slowly double clutching in a manual and then slams into 3rd,I’ve been talking to the tuner and he’s got no idea what could be causing it,I’ll chuck up a copy of the tune and do a log and chuck that up aswel 2morro arvo

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