4l60e 2-3 slipping shift

[Wade]

The kph vs tps upshift seem to have an impact on shift pressure settings. So if you go in and change them you’ll then need to go in after and tweak the pressures. Most people just add shift pressure straight up, but I recommend getting the tps vs kph shifts where you want them first, then play around with shift pressures. For me it’s personal preference. I’ll make slight changes and then let all the adaptive stuff relearn and if I’m still not happy after that I go back in and make changes and repeat. Holden seemed to make heaps of changes throughout the years with the normal and performance upshift pressures.

[vscapricetim]

Fluid didn't look aerated, still pink and doesn't smell of being burnt.

[vscapricetim]

The kph vs tps upshift seem to have an impact on shift pressure settings. So if you go in and change them you’ll then need to go in after and tweak the pressures. Most people just add shift pressure straight up, but I recommend getting the tps vs kph shifts where you want them first, then play around with shift pressures. For me it’s personal preference. I’ll make slight changes and then let all the adaptive stuff relearn and if I’m still not happy after that I go back in and make changes and repeat. Holden seemed to make heaps of changes throughout the years with the normal and performance upshift pressures.

So are you talking forcemotor - pressure offset vs tps? My 3rd gear from say 75% up is 55.

[Wade]

Yeah offset gear change pressures

[Deuce]

Could be the adaptive shift settings. I’ve found the shift pressures are pretty good but the shift times are not. Simply lowering the adaptive shift times down to something similar to what holden used in the ls1’s makes a huge difference. Changing shift kph vs tps can also make a huge difference as well as tcc lockup. I’d recommend setting those tables before modifying any shift pressures as I’ve noticed changing shift kph vs tps has an impact on that. But yeah the adaptive shift times makes a huge difference. I could get my 4l60e shifting as if it had a shift kit just via lowering those shift times. I’m now running a transgo pro kit in mine and very happy. Drives fine a to b but progressively gets firmer the more you mash the peddle

Great info.
I was at the track earlier this month (VR V8, 11p) and hade to lower my 2-3 shift rpm at WOT to compensate for a very lazy and slow 2-3 shift.
Everything seemed to be going fine, just this horribly long wait between 3rd gear commanded and actually seeing rpm dropping to indicate the completed shift.
2+hr drive home was perfectly fine and normal.
I'll fire up the laptop later and see what they look like.

[Wade]

There’s temperature based tables as well

[delcowizzid]

Once you start making enough torque they start to slow change on the 2-3 and will quite often smack the limiter a couple times before shifting even the t700r4 with a full manual shift kit does it at around 10-12psi of boost

[immortality]

Yeah offset gear change pressures

That would only really work at lower TPS/RPM's? At WOT and high RPM you are basically at max commanded line pressure already.

So, that begs the question, does the PCM use a PWM function on the shift solenoids? There is a PWM solenoid for the TCC apply but nothing similar for the 1-2, 2-3 solenoids?

I'm genuinely interested how the electronic side interacts with the transmission Vs manually shifting the box via the shifter in the car? I bring this up because I know on this car,

Could be the adaptive shift settings. I’ve found the shift pressures are pretty good but the shift times are not. Simply lowering the adaptive shift times down to something similar to what holden used in the ls1’s makes a huge difference. Changing shift kph vs tps can also make a huge difference as well as tcc lockup. I’d recommend setting those tables before modifying any shift pressures as I’ve noticed changing shift kph vs tps has an impact on that. But yeah the adaptive shift times makes a huge difference. I could get my 4l60e shifting as if it had a shift kit just via lowering those shift times. I’m now running a transgo pro kit in mine and very happy. Drives fine a to b but progressively gets firmer the more you mash the peddle

Great info.
I was at the track earlier this month (VR V8, 11p) and hade to lower my 2-3 shift rpm at WOT to compensate for a very lazy and slow 2-3 shift.
Everything seemed to be going fine, just this horribly long wait between 3rd gear commanded and actually seeing rpm dropping to indicate the completed shift.
2+hr drive home was perfectly fine and normal.
I'll fire up the laptop later and see what they look like.

Shifting it manually it shifts fine but allowing the PCM to do the change electronically causes the problems at WOT but shifts fine otherwise.

[Wade]

I think there’s a scaler set at max 90psi so you’re probably right about wot

[Deuce]

Once you start making enough torque they start to slow change on the 2-3 and will quite often smack the limiter a couple times before shifting even the t700r4 with a full manual shift kit does it at around 10-12psi of boost

Yeah, that sounds like mine.
1-2 from commanded shift until minimum rpm point in 2nd (start of accel in that gear) approx 1sec.
2-3 from commanded shift until minimum rpm point in 3rd, approx 2.5seconds.
Lazy!!