GQ Auto questions

[flyingbrick]

Both would be great- though the $1500 part sounds ridiculous! Would be the most expensive upgraded valve body i've seen

I'd love to know how they did what they did- EG shimmed accumulators, etc etc.

Right now its pretty much safe to say i know nothing. I'm not too bad with electrical stuff (built my own megasquirt ecu and that worked lol) but really at this stage would like to know:

Pin diagram for the trans ecu plug(s)
Which solenoids have to be energized to select which gear.
Wiring diagram for ECU independent line pressure setup would be great too

And then, lastly- I'm not sure i totally understand how the factory trans ECU works with the actual gear selector lever. With your setup do you simply use the lever for P, N and D and 2 and 1 do nothing?

How do you switch each of your relays on/off? I'd ideally like to find/build a simple circuit to scroll up and down through the relays using two switches.

-Nathan

[darinz]

It sounds like a lot when compared to T350-400 stuff but then you aren't paying for R&D on those anymore. When you look at the costs of converting to one of those to get full manual then it is a cheap way of doing it.

From the factory the tcu controls the solenoids direct and also the line pressure. What we did was take a signal from the inhibitor switch and used that to switch the relays. One relay per gear. You must move the shifter to get engine braking.
Mine was set so that 'L' was 1, '2' was 2, 'D' was 3 and the power switch was 4. I also have a switch for the lock up.
It is quite simple and just followed the wiring diagram to find the relevant wires at the TCU plug.

I don't have a pin diagram for the tcu as we never bothered to use it.
With how my auto woks now I don't think I'd bother with any line pressure control and would just leave it at full pressure all the time. Particulary if you are running a modified TD42 or above.

There are 2 shift solenoids, shift A and B, their is an over run solenoid but I didn't switch this at all. Then line pressure and lock up. So with experience I would only worry about the shift and lock up solenoids and leave the rest fully closed. My new VB has only 2 solenoids instead of 5. ie lock up and 4 gear. Everything else is now hydraulic or not used eg no over run control or line pressure control

I'll try and dig up the wiring diagram we used for the relays as that is all there really is to it. The hardest part was identifying the wires as we only have 12v factory WD and it is 24v truck so colours are different and some extra wires. Once you figure out which wires go where the wiring of the solenoids and the inhibitor switch is very simple.

[flyingbrick]

Thanks for that- explains tons. I did not realize that your valve body actually was a manual valve body- I thought it was just a modified factory body to raise pressure and firm things up (these are available fairly cheap for the nissan i am told)

is only one of the 4 solenoids usually energised at any one time? What happens if you were to click the power button while in 1st, or 2nd stick positions? would it get confused or have you simply put relays in to break the other 3 relay circuits when that button is depressed?

Wiring diagram would be great.

Thanks tons dude. You go a long way towards making this club as good as it is

-Nathan

[swampa]

just a fraction off topic, does anyone know the length of safari gq auto from front of bellhousing to rear of transfercase, sorry about this,
karam

[darinz]

I used a relay for each gear so that you can only select 1 gear at a time. Also the power switch (4th) has it's power supply controled by the shifter being in 'D'. So when you select the relevant gear that actually switches a relay not the soleniods directly. Basically it is only the shift A and B solenoids that you control so second gear (I think) is both solenoids off so if fact without power 2nd gear is the limp home mode.

If you get that bar I can go over everything with you and show you what is left of our mark 1 and mark 2 versions of it.

[flyingbrick]

I used a relay for each gear so that you can only select 1 gear at a time. Also the power switch (4th) has it's power supply controled by the shifter being in 'D'. So when you select the relevant gear that actually switches a relay not the soleniods directly. Basically it is only the shift A and B solenoids that you control so second gear (I think) is both solenoids off so if fact without power 2nd gear is the limp home mode.

If you get that bar I can go over everything with you and show you what is left of our mark 1 and mark 2 versions of it.

That clears up just about everything i wanted to know, thanks! I've flicked you an e-mail about the bar.

Cheers dude, you rule

-Nathan

[flyingbrick]

Thanks for all the info guys I just did the lockup tq converter switch- I have CPU/sensor issues and the easiest solution was to simply remove CPU dependence. Pretty cool how instantly it locks up! it has far more grab than expected (did testing at like 50kph )

Once im home i'll wire in another relay so that it only operates in D/2/a and not in park.

Here is a very usefull wiring diagram for anyone wishing to screw with the auto trans.. unsure if its been posted here yet- i didnt see it. the grey/red wire in pin 22.

[darinz]

So have you done the full manual conversion or just the lock up? ( I never did scan those wiring diagrams for you)
The lock up clutch is strong enough to stall a TD42.
I'm in the process of getting my stall speed increased and will just use the lock up more if engine braking is an issue. I don't like engine braking as I think it is something inexperienced people rely on rathering than using the braking correctly.

[flyingbrick]

So have you done the full manual conversion or just the lock up? ( I never did scan those wiring diagrams for you)
The lock up clutch is strong enough to stall a TD42.
I'm in the process of getting my stall speed increased and will just use the lock up more if engine braking is an issue. I don't like engine braking as I think it is something inexperienced people rely on rathering than using the braking correctly.

Just the lockup clutch- but have all pins etc written down and everything organised for the manual conversion (I've got a pile of relays sitting here.. looks beautiful). If you could scan that diagram it'd be great just so i know i'm on the right track. It took me a while to kinda understand what the inhibitor switch actually was and how it all worked but that wiring diagram i just posted helped shitloads. Its all far simpler than it first seemed.

Of more use to me Darin would be the 5v supply you mentioned- jsut to clarify- 5v gives you maximum line pressure? (yuo were talking about something up there DROPPING in voltage as RPMS rise, hence my confusion)

Hows your truck coming along after the bottom end failure?

-NAthan

[darinz]

At full line pressure there is 0v. ie the solenoid is fully closed. The more power to the solenoid the more fluid it bypasses and so reduces the pressure. So if you want max pressure all the time, then no need to supply any power.

I've got to remember to take the diagram to work as I don't have a scanner at home. It is pretty rough but you should get the idea.

We were considering stripping out a TCU so that we could run it manual and then switch back to auto by just unplugging one and putting the other back in. Never got around to it but if you want to spend the time then an option.

I'm pulling the motor out tomorrow. Most of it is undone so just have to lift it out now. We're quite confident that it isn't a big end but something further up so maybe a piston or something like that. Doesn't matter really as the motor will have to come apart any way you look at it.

[flyingbrick]

At full line pressure there is 0v. ie the solenoid is fully closed. The more power to the solenoid the more fluid it bypasses and so reduces the pressure. So if you want max pressure all the time, then no need to supply any power.

I've got to remember to take the diagram to work as I don't have a scanner at home. It is pretty rough but you should get the idea.

We were considering stripping out a TCU so that we could run it manual and then switch back to auto by just unplugging one and putting the other back in. Never got around to it but if you want to spend the time then an option.

I'm pulling the motor out tomorrow. Most of it is undone so just have to lift it out now. We're quite confident that it isn't a big end but something further up so maybe a piston or something like that. Doesn't matter really as the motor will have to come apart any way you look at it.

Thanks Darin. Once again you have answered all of my questions and then some

have tapped into the required wires just before the ECU plug with my own plug so that everything's removable and reversible should i #### it all up. Its my daily driver and need to do stuff like that to keep my stress levels down

Thanks again,
Nathan

edit:
Any idea what the purpose of the dropping resistor is at pin 33? cant wait to get out there tomorrow for a snip of 33 and 34's wires.

[flyingbrick]

cut the wires. Doesn't feel like its really done much. MAYBE its shifting a little faster and maybe its holding gears a little longer than before.. but its negligible. hmmmmmmnnnnnnnn.

edit:

I lied. Auto must have been slipping bigtime and losing power in the process. Hope its all ok-I took it for a real decent drive. Very very nice now that ive cut those two wires and seems a crapload faster off the line/shifts gears way way way nicer.

This weekends been pretty productive considering how much i tend to procrastinate.

[darinz]

At a guess, I would say the dropping resistor is to do with line pressure and gear change. I would say that it cuts line pressure on gear change so that it is smoother shifting.

That is a guess though!!!!!

The big thing you do not want to do is drive it with low line pressure as this will cause a lot of slip and burn the frictions.

[flyingbrick]

At a guess, I would say the dropping resistor is to do with line pressure and gear change. I would say that it cuts line pressure on gear change so that it is smoother shifting.

That is a guess though!!!!!

The big thing you do not want to do is drive it with low line pressure as this will cause a lot of slip and burn the frictions.

the problem was that my TPS sensor went bad - it showed by throwing a fault code- the TQ converter would pulse on/off at 100kph depending on where the throttle was (it was terrible.. totally sporadic) and I kept saying "i'll fix it next weekend" untill i found myself up thompsons and while reversing in 2wd with the wheels heavily loaded (but still on grass/clay) the trans started slipping.

So I'll assume that the bung TPS meant it was not ramping the pressure up to match throttle inputs.

Doing removing the cpu's control of tq converter and pressure has made it feel totally awesome however- so i'll assume- for now atleast- that all is well.

dont forget to scan that diagram. Write it on your arm with a permanent marker... and then put an arrow on your hand to remind you to look at your arm.

[darinz]

Since I'm stuck at home with a few stiches in my knee curtiousy of a VH45, I can't even get inti a car to go to work!!!!!!

[flyingbrick]

Pics or it didn't happen!

[darinz]

Didn't take any but having just spent a night in hospital with it I can assure you that bones really are white!!

[flyingbrick]

yuck!

Ok well since you have time to kill.. ahaha... can you tell me what the over run solenoid does.

something to do with engine braking?

[flyingbrick]

Well my manual shift setup is finished- but not installed.

Have put a plug on so i can swap it with the factory ECU if i get sick of it.