VZ Auto Transmission Fix

[vex]

Hi Guys,

Ive been searching around the internet for 6 months now trying to find a fix to the common problem of the auto boxes in the commodores (and various other american models). The problem is the harsh gear changes. There are so many different threads on various websites but no-one has ever posted a fix for it , only possibles. I'm asking if anyone has actually found a fix (had yours repaired or did a fix on a mates car), i have had it rebuilt already and that was ok for 2 weeks. So once again anybody had it repaired? there have been 100's of threads on this website alone!

[Moey]

I'd read a while ago somewhere, that it was put down to a dirty sensor in the gearbox (on the flywheel or somewhere around there). I've owned a VT and two VZ's, neither of them had the harsh gear changes.

I know what you mean though, I did drive some else's VT a long time ago - and the gearbox changes were rough.

[VZ_commo91]

Mine changes from 1st to 2nd pretty hard, But I like that Only does it when its cold though... I wanted to put a corvette servo into my VZ.

[Paul13pp]

Hi Guys, The problem is the harsh gear changes.

Does it log a fault code at all?
My VS suffers harsh 1st to 2nd changes as well as reverse and 1st when going from park to drive/reverse. Changes to 3 and 4 are very smooth.
There is a fault code logged which I believe says a solenoid fault in the transmission.

VZ may be very different though.

[vex]

no i doesnt have any codes according to holden. I have also replaced the 1-2 solenoid with no change. im thinking maybe the throttle position sensor. I have also heard that tweaking the computer can make a difference? anyone fixed it?

[cavz]

Yeah, I had solenoids and pressure switch replaced in mine but what finally solved the problem was getting the computer settings altered. It's not 100% but a hell of a lot better.

[vex]

how much was it to get the computer tweaked? Does anyone know the name of that sensor that is apparently near the flywheel?

[cavz]

They did it when they replaced the pressure switch so it was included in the labour which was 1.5hrs at your standard mechanics rates.
They had to change the computer settings to match the new pressure switch.
Don't ask me what the pressure switch does, I know nothing about autos.

[heyitsEnricoPallazzo]

Sounds like the force motor (EPC) solenoid was replaced or modified.

[vex]

so guys, anyone else got any idea?

[Phyco]

so guys, anyone else got any idea?

My issue with harsh gear changes between 1st and 2nd only occurred occasionally, and it would disappear after a few restarts. The problem has not shown up for more than six months, ironically since I had VCM suite run and the ECU tuned.

[Torquative]

also the Corvette Servo makes it harsher as thats what its designed to do

I had a shift kit and servo in mine and had to put a new gearbox in, as the shift kit was waaaay too harsh for normal driving (worked well under load though) and once we tried to "return it to stock" we kept having issue after issue.

At one stage I ended up wih a gutted 4L60E at my place trying to replace parts in the hope we could do it, just for some reason she never went back together properly!

[ScufVZwags]

also the Corvette Servo makes it harsher as thats what its designed to do

I had a shift kit and servo in mine and had to put a new gearbox in, as the shift kit was waaaay too harsh for normal driving (worked well under load though) and once we tried to "return it to stock" we kept having issue after issue.

At one stage I ended up wih a gutted 4L60E at my place trying to replace parts in the hope we could do it, just for some reason she never went back together properly!

Hey mate just wondering did u blow ur auto up. Iv got servo and boost valve in my auto. My auto blew up bout a week ago