GQ auto trans - hold in gear

[Vulcanised]

Can it be done? is there some kind of control i can put in place by messing with the wires on the ECU to hold the trans in the gear that is currently selected?

yes i searched I suck at searching

[ausoops]

its only a four speed box with over drive. use the gear selector to hold it in gear?

1 - 2 - D(with pow button = 3rd) - D without pow is 4th - overdrive


but in saying that, the throttle bodies are electronic so you need to tap in line into the trigger wires and switch them

[CRUSHU]

I have a switch on the dash that says hold. I've never used it, but i assume it olds the current gear?
Mine is a series 2 EFI.

[Vulcanised]

its only a four speed box with over drive. use the gear selector to hold it in gear?

1 - 2 - D(with pow button = 3rd) - D without pow is 4th - overdrive


but in saying that, the throttle bodies are electronic so you need to tap in line into the trigger wires and switch them

if i want to hold it in say low 2nd, and give it a boot full, it will change back to 1st and rev crap out of the engine... i want to be able to put it in low 2nd and for it to start in that gear and hold it there. I figure if i knew which trigger wires to use, u could tap into them the same way i did with the torque converter lock up.

[PGS 4WD]

Speak to Paul or Dave at Kewish autos in dandenong they do heaps of these in various guises for comp trucks and theyre great guys.
Joel

[raptorthumper]

I'm with you patrolden. I would love mine to be fully manualised. I would like full control of when the auto changes, and for immediate speedy shifts.

Grant.

[ausoops]

how electrically minded are you? after looking at the schematics for the auto box it would be possible but would require a lot of hacking into the harness that comes out of the auto transmission control unit. but if you have already done the torque converter lock-up it should be easy.

pm me your email address and ill email you the schematics. maybe get a google account as it is 18mb.

[Vulcanised]

how electrically minded are you? after looking at the schematics for the auto box it would be possible but would require a lot of hacking into the harness that comes out of the auto transmission control unit. but if you have already done the torque converter lock-up it should be easy.

pm me your email address and ill email you the schematics. maybe get a google account as it is 18mb.

thanks dude! you rule i have already hacked into it for the lock up. another switch for holding gears would be great!! My email allows for emails that big.

[MrMaxi]

can you post a link to the instructions on how to by pass the lockup ? I've got a convertor that has been doing it's own thing for the last 18 mths, is it ok to do as long as your not towing ? I use stockies for daily use.

[jtraf]

My TD42 auto has a the power/auto/hold button near the radio.

If you put it in hold it will start off in second even if in D. In Europe it was labeled snow.

I have never needed to do it but I have read that is what that switch is for

[Vulcanised]

can you post a link to the instructions on how to by pass the lockup ? I've got a convertor that has been doing it's own thing for the last 18 mths, is it ok to do as long as your not towing ? I use stockies for daily use.

i can't remember the colour of the wire or the loom number, but Keith (ST391GQ) has it in his Datsun bible It's easy as piss to do. Just need a 12v supply and by-pass the ECU. I wouldn't not use it..... but you have more control over it, even towing, I leave mine locked and use 3rd gear as well, kinda gives you a split between 3rd and 4th gear. usually works well.

[Vulcanised]

ok... i got my hands on a schematic for the model with the hold button..... i think i have sussed it out..... by the look of it, i need to switch the wires i have marked on the ECU.....

i won't post the pic here.... too big. You can look at it here though,

http://www.downunder4x4.net/holdswitch.jpg

am i heading in the right direction?

[lwbmav]

I have a switch on the dash that says hold. I've never used it, but i assume it olds the current gear?
Mine is a series 2 EFI.

Yep thats the same thing my GQ 2 had, I just choped it out of the loom .
So if you need wire colour or whatever let me know.

cheers Scott

[Vulcanised]

i have looked at the diagram for my trans as well as the others.... seems that it's all the same except for the wiring that works the "hold" feature. from looking at them, it would appear that if i plumb a 12 volt supply into socket number 27 on the trans ECU, it should for all intents and purposes work.
Thats a green wire with a red stripe on the models with the hold feature..... on my ECU that part of the loom is blank, so i should be able to make it work......

[GUJohnno]

i have looked at the diagram for my trans as well as the others.... seems that it's all the same except for the wiring that works the "hold" feature. from looking at them, it would appear that if i plumb a 12 volt supply into socket number 27 on the trans ECU, it should for all intents and purposes work.
Thats a green wire with a red stripe on the models with the hold feature..... on my ECU that part of the loom is blank, so i should be able to make it work......

Did you do this and how did you go?
I'm using this diagram but need to know which wire to tap into..

[nzdarin]

I took the tcu out of mine and ran it with 4 relays so it was completely manual. The hardest thing was getting a 5v supply for the line pressure solenoid. This was run through the TPS direct to the solenoid and gave control of line pressure.
I've now fitted an extreme manual valve body (from Wholesale Automatics) and that is a whole new level. It doesn't have any pressure control (just runs max pressure) so is great offroad but a bit hard for a DD. It also doesn't use the acumulater piston spring so changes are rather hard. A bit like a manual. It also has lock control in al gears etc. But there is no auto control at all.

[GUJohnno]

OK all sorted out now and wrapped with it.
As per this diagram (click on link) you need cut into the Grey wire with Red stripe.
http://www.downunder4x4.net/holdswitch.jpg

The only thing I had to do different from the wiring diagram above is we had to swap the 85 & 86 wires over on the brake light relay.

It pulls heaps harder through the gears when excellerating, seams like about 5-10% better. Auto and engine temps are staying lower as well.

[MKarmyshev]

Can you please explain a bit about this diagram?
On my Safari there is only a "Power" button on the gear selector itself.
Where do I have to connect a "Hold" switch?

[GUJohnno]

Can you please explain a bit about this diagram?
On my Safari there is only a "Power" button on the gear selector itself.
Where do I have to connect a "Hold" switch?

Have a look here
http://members.bettanet.net.au/~conody/ ... Switch.htm
most of your questions should be answered there.
The only difference was the color wire from the GU to GQ's

[GUJohnno]

...It pulls heaps harder through the gears when accelerating, seams like about 5-10% better. Auto and engine temps are staying lower as well.

I have since found out that it's not the best idea to do this. I.e. accelerating away with it locked up.

The GQ diesels have a smaller converter as it has a big steel band around it that takes up some room.
The first weekend away the converter let go sending metal all through the box. It's now getting a full rebuild and costing over $3,000

The lock up switch is good for cruising at 100km/h and towing and also for down hill off road where there is no accelerator input to help eliminate the run on you get with auto's.

[MONSTATROL]

Hi there, I read a few posts up that the gear pattern in the Auto is 1-2-D with over drive. Mine when I activate overdrive has two speeds? I also have the Auto hold button on the Dash near the radio, which doesn't work.

[Dak]

Overdrive doesn't have two speeds to speak of, what you are feeling is the torque convertor lockup.

Cheers, Jeff.

[GUJohnno]

The earlier models have the 1-2-D with an overdrive.
On the shifter there is a power button which holds it in 3rd gear, stopping it from going into overdrive.

When the auto is up to temperature the torque converter locks up which lowers the revs. This is what you feel as another gear.

I'm not sure about the switch on the dash as the earlier models (such as mine) doesn't have this.

[GUJohnno]

From the GQ manual.

On series II vehicles, the selector leaver push button switch controls the overdrive selection. When pushed in, the transmission will up shift into overdrive as the vehicle speed increases. When the button is released, overdrive cannot be selected. This position is advantageous when engine braking is required or when constant changes from third gear to overdrive need to be avoided.

A separate switch selects Power, Auto of Hold mode. Power mode is used for rapid acceleration or up hill driving. Hold mode is used to hold which ever range is selected on the selector leaver, i.e. first, second, third or overdrive. Hold mode is useful during standing starts on slippery surfaces.