GQ Auto questions

[Muzza]

Could you please help answer 4 questions for me regarding the operation of the auto in my 92 SWB GQ which has an aftermarket turbo fitted.
1. When cold it does not wont to engage overdrive untill it has traveled a few K's ( 6-10 ? ) and presumably warmed up.

2. What does the HOLD-POWER-AUTO switch do. I assume Power and auto are fairly self explanatory and I have found that HOLD seems to lock it into 2nd gear when in low range. I have put in low range reduction gears which has made a huge difference to its offroad ability and it would be nice to also be able to lock it in 3rd as on steep climbs it will kick down to 2nd causing a loss of momentin when in fact the truck has plenty of power to hold 3rd.

3. Is my Overdrive lockup clutch disengaging to easily ?. When engaging Overdrive the torque converter steps up allright and drops engine revs and then a second or 2 later the lockup clutch engages dropping the engine revs another 1-200 rpm. This seems all normal and good so far and it will stay locked in when cruising or under load but as soon as the load comes of like slowing down for a corner or going down a hill the lockup clutch disegages and then when the load comes back on the lockup clutch has to reingage again. In some situations this can be happening quiet frequently. Is this normal and does it wear the lockup clutch.

4. Oil level. My dipstick mark has COLD on it. I assume I take the reading with the oil cold, motor running and auto in neutral.

I have a bad electrical connection in my instrument cluster as sometimes my speedo and odometer does not allways work straight away when cold but this does not seem to affect the auto in any way even regarding question 1 .
Some where along the way I read something about the solenoids in the auto can fail causing damage to the auto ? Is this correct and what symptoms does it exhibit.
Any other info on fine tuning these auto's for offroading would be much appreciated

Cheers

[DieselBoy]

Could you please help answer 4 questions for me regarding the operation of the auto in my 92 SWB GQ which has an aftermarket turbo fitted.
1. When cold it does not wont to engage overdrive untill it has traveled a few K's ( 6-10 ? ) and presumably warmed up.

Yep, correct, it is to ,ake the engine warm up quicker, once a certain temp has been reached, it allows over drive to engage.

2. What does the HOLD-POWER-AUTO switch do. I assume Power and auto are fairly self explanatory and I have found that HOLD seems to lock it into 2nd gear when in low range. I have put in low range reduction gears which has made a huge difference to its offroad ability and it would be nice to also be able to lock it in 3rd as on steep climbs it will kick down to 2nd causing a loss of momentin when in fact the truck has plenty of power to hold 3rd.

As you said, it allows you to hold it in 2nd low, and in high range it disable sthe kick down. It "should" also disable the kick down in low range aswell. Power just means it alows the engine to rev higher before gear changes.

3. Is my Overdrive lockup clutch disengaging to easily ?. When engaging Overdrive the torque converter steps up allright and drops engine revs and then a second or 2 later the lockup clutch engages dropping the engine revs another 1-200 rpm. This seems all normal and good so far and it will stay locked in when cruising or under load but as soon as the load comes of like slowing down for a corner or going down a hill the lockup clutch disegages and then when the load comes back on the lockup clutch has to reingage again. In some situations this can be happening quiet frequently. Is this normal and does it wear the lockup clutch.

Welcome to the Nissan experience. Thats how they are programmed. You can set it up so the lock up is on a switch which makes driving along a winding road less painfull

4. Oil level. My dipstick mark has COLD on it. I assume I take the reading with the oil cold, motor running and auto in neutral.

Yep, and also should have a hot mark, follow the same proceedure for hot.

I have a bad electrical connection in my instrument cluster as sometimes my speedo and odometer does not allways work straight away when cold but this does not seem to affect the auto in any way even regarding question 1 .
Some where along the way I read something about the solenoids in the auto can fail causing damage to the auto ? Is this correct and what symptoms does it exhibit.
Any other info on fine tuning these auto's for offroading would be much appreciated

Cheers

Computer controlled, so not a lot you can do easily, besides putting the lock up switch on. With the hold switch enabling to lock the trans into 2nd low when off road is a feature that not many other vehicles have, so enjoy!!!!!!

[Muzza]

Thanks for that info DieselBoy

It never hurts to ask the simple questions first!

I had a good play with the HOLD-POWER-AUTO switch this afternoon now that I know what it should be doing and it seems to be working OK although I suspect it might not have been to start with.

You said "You can set it up so the lock up is on a switch which makes driving along a winding road less painfull". How do I wire this up. ( I assume you mean to hold the overdrive lockup clutch in as opposed to what the POWER switch does.)

Cheers

[DaveM]

Not sure if this is the type of setup DB is talking about......
http://www.juland.com.au/translocker.htm

[Muzza]

HHHhhhhhhmmmmmmmmmm
Don't know if it is Dave.
I hope not because it looks like $$$$$$$$$$$$$$$$$

Before I was looking at auto's I remember someone talking about having rigged up a switch on their shifter to lock it up manually but you had to remember to turn it off. It would certanly make the truck more enjoyable to drive on road if I could stop the Overdrive from "Hunting" because the turbo'd motor with an auto and crawler gears in the transfer case is awesome offroad.
I think I saw where you were driving an auto now ?

Cheers

[DaveM]

Not sure on the price of that unit, but there are similar ones available for around $150aus.
You can also make them yourself, there are plans on another forum, and although they are for a 3.0 GU, I'm sure they can be used on others

[DieselBoy]

You said "You can set it up so the lock up is on a switch which makes driving along a winding road less painfull". How do I wire this up. ( I assume you mean to hold the overdrive lockup clutch in as opposed to what the POWER switch does.)

Cheers

I know it can be done by simply cutting one wire and puting a switch into the circut, much like this (although this is a Terrano, the A/T management systems are basically the same). I just so happen to have an Auto Safari sitting in the garage at the moment (rats ate some of the wireing), so i can have a look tonight.

I can't find the article i wrote on the mod, might have been lost somehow. Will see what i can sus out, I posted the article on another Forum aswell.

[Shane]

I have run a switch direct to converter lock up solenoid,completely manual so you have to remember to turn it off.
very easy to do and can lock up in 2,3,4 gears.probley one of the best cheap mods I've done.

I can get the lock up wire colour if you want?


Shane

[NJV6]

With the switch you guys have put in to lock the TC, if you have the TC manually activated, does it still change down a gear (say 4th to 3rd) with a hard prod on the throttle? ie. Can the auto still work with the TC locked?

[PR]

I have run a switch direct to converter lock up solenoid,completely manual so you have to remember to turn it off.
very easy to do and can lock up in 2,3,4 gears.probley one of the best cheap mods I've done.

I can get the lock up wire colour if you want?


Shane

Yes please can go with the 50% reduction gears I am about to put in

[Muzza]

I can get the lock up wire colour if you want?

Thanks Shane, that info would be good.
I assume the solenoid is in the auto box and you tap into the wire somewhere between the box and the computer ?.
DieselBoy was going to have a look at some info he had to.

[DieselBoy]

I can get the lock up wire colour if you want?

Thanks Shane, that info would be good.
I assume the solenoid is in the auto box and you tap into the wire somewhere between the box and the computer ?.
DieselBoy was going to have a look at some info he had to.

Yep, what shane is talking about was what i was going to say, i had done a write up but its vanished

I thing it was a blue wire located in the engine bay.

Shane, grab a photo of where the wire is located, and its colour and maybe we throw this thread into the Tech section to replace the lost thread!!!!

[darinz]

With the switch you guys have put in to lock the TC, if you have the TC manually activated, does it still change down a gear (say 4th to 3rd) with a hard prod on the throttle? ie. Can the auto still work with the TC locked?

Yes it will still change down but it is a pretty hard shift!
I've gone a few steps futhur and actually did a complete manual shift conversion on mine. I did it first by removing the computer and replacing it with a series of relays and controlled the line pressure directly from the TPS. This worked pretty.

I have now gone a step furthur than that and have a complete manual valve body for it (from Wholesale Automatics in Melbourne). This is an amazing upgrade as it is basically a clutchless manual now. It runs increased line pressure so has less slippage and better engine braking and also runs cooler. Take into account I have 280kw at the wheels and the auto doesn't overheat at all. Well it hasn't in the past 12 months since it has been going. I can change gear at full throttle on the rev limiter and it is very very smooth. At low revs and no load, well then it is a bit rough!

The biggest problem with a the Safari (and Terrano) auto is the factory oil cooler. As the torque convertor wears, it drops particles and these block the factory cooler due to small (but efficient) passage ways. Once these are blocked that reduces the oil flow to the gear set. This then melts and basically destroys the entire trans. The easy fix is to service and change the filter regulary and get a rebuild done BEFORE it dies as you will save about $1500 to $2000 on the job. ie I got mine rebuilt and upgraded including torque convertor mods and increased clutch pasks etc and it was only $3k.

Oh yeah Nissan electrics suck badly and before you question anything inside the auto, you can almost guarantee it will be a TPS fault or a broken wire! But with the right mods it will reliably handle 600hp (450kw).

[Muzza]

Darinz wrote
"The biggest problem with a the Safari (and Terrano) auto is the factory oil cooler. As the torque convertor wears, it drops particles and these block the factory cooler due to small (but efficient) passage ways. Once these are blocked that reduces the oil flow to the gear set. This then melts and basically destroys the entire trans."

This is what I had heard so have put in an aftermarket cooler and changed the filter and oil.
While searching other forums to try and find the right wire to tap into for my manual lockup switch, some of the info I have read suggests that using the lockup below 1800 - 2000 rpm ( common offroad ) may cause the lockup clutch to slip as it may not have full pressure and hence increase wear resulting in clutch particles blocking the coolers. Using the lockup switch in effect turns it into a manual and although it gives you increased engine braking and no torque convertor slip it places a big load on the lockup clutch. This is the advantage of putting in special mods like Darrins. link to http://www.automatictransmission.com.au/default.asp
I only need a simple switch as I primarily want it to hold lockup in overdrive when cruising and to eliminate slip ( hence temperature ) when towing in 3rd. Even the fancy aftermarket switches seem to allow only about 10% variance in speed.
I reckon that when offroad alot of the advantage of an auto is in it's soft power delivery.
Still cant work out which pin number/wire colour I need comming out of the A/T control unit. Feeding 12 volts into the correct wire enables lockup. I could use a voltmeter to check voltage when engaged but that looks abit tedious.
Found lots of wireing diagrams and fancy home made systems but different ATC's than mine. http://www.chaz.yellowfoot.org/Lockup%2 ... Switch.htm
Pics of mine
Cheers

[Shane]

Wire on 24v diesel model(1990)is a Gray/red stripe,I run 24v direct to solenoid when turned on(locks up very quick)when testing I found that factory lock up ramps the voltage up,my guess would be smoother engagement.

When 4wding I almost never use the lock up(just not needed)sometimes its useful when on steep(driving up)high country type tracks were your doing 20-40kph and the converter is working hard just makes it easier on everything.

when traveling on roads once up to speed I have it on 90% of the time,on road is were I find it makes a huge difference esp. when on big tires,with a good lift(I hate to think what the CD of my truck would be )






in the above pic you can just see the white wire that connects to gray/red,I have by passed the computer completely and is full manual operated by the driver with switch,I find this works fine for me,I could put a change over relay so it works as std till I flick the switch and over ride it,may do this one day.

Shane

[Muzza]

Thanks Shane. The pics are showing but no comment, so still can't see exactly what you have done.
Cheers

[Shane]

Thanks Shane. The pics are showing but no comment, so still can't see exactly what you have done.
Cheers

sorry muzza,someone else needed the computer,have added some words

Shane

[Muzza]

Thanks for that Shane, I can see exactly what you have done. Just what I wanted.
Only one question though ? From what I had been reading on the forums I thought the solenoid was powered by 12volts ( accessories power source is an options ). I will have to recheck this as my truck is the same as yours 24v and they might have been referring to 12v systems which could be different.

Auckland has peak hour traffic congestion - you must suffer from the same problems as me - peak computer demand periods
Thanks for all your help. Much appreciated
Cheers Murray

[PR]

Cheers Shane

[PigFmr]

shane done mine about 8mths ago ,great for going over porters pass ,made a hell of a diffrence
Vince

[Shane]

Thanks for that Shane, I can see exactly what you have done. Just what I wanted.
Only one question though ? From what I had been reading on the forums I thought the solenoid was powered by 12volts ( accessories power source is an options ). I will have to recheck this as my truck is the same as yours 24v and they might have been referring to 12v systems which could be different.

Auckland has peak hour traffic congestion - you must suffer from the same problems as me - peak computer demand periods
Thanks for all your help. Much appreciated
Cheers Murray

once you track down the wire,back probe it(no pun intended )with M/meter and see what the voltage is there when lock up comes in pretty sure mine was 22ish volts.

[Muzza]

once you track down the wire,back probe it(no pun intended )with M/meter and see what the voltage is there when lock up comes in pretty sure mine was 22ish volts

Thanks Shane.
I was one step ahead as thats exactly what I have been trying to do but can't find my multimeter. Dam!
Just spent the last 2 hours looking for it , ducked around to a mates place and borrowed his but his meter was dead. I should go back to bed as it might be one of those days.
Cheers

[darinz]

I just had great reply with a lot of detail and then a brain fart deleted it all!!!!!!!!!!!
So the simple reply is..
12v = 12v solenoids
24v = 24v solenoids

Line pressure is at max pressure from not far above idle. A TD42 has max torque at 2000 rpm so line pressure is well and truely up by then. At idle TPS supplies 5v to LP solenoid and it drops to 0v very quickly eg before 1000rpm. The first manual conversion I did I ran 3.5v at idle and it dropped to 0v at 800rpm. This worked very well. You have to remember that at reduced line pressure the clutches inside the auot will slip and this causes wear and heat so reduced line pressure will damage the auto very quickly. Line pressure is like clutch pressure in a manual, so to get more grip you increase the pressure (or surface area)

The computer supplies a pulse signal to the lock up solenoid which is why the reading your guys are getting is variable. Supplying a constant power supply to the standard solenoid will cause a reduced life but the reality is you won't notice it as the auto will need an overhual by then anyway.

If you want a manual conversion I've worked out the wiring so can help with it.

[Muzza]

Hi Darinz.
Have been away for a few days so before I left I quickly rigged up a rocker switch on the front of the shifter so I could flick it on and off with my left thumb. Boy, this is definately a must do mod ! - Truck drives way better (Have done some towing and cruising). Very happy
Great keeping it locked up when cruising or when in Drive on windey roads or opt to leave it out when accelerating or need more revs. I realize it is not a strong clutch so tend to nurse it a bit, but manual activation must prolong the clutch life as it's not switching in and out, and when you do engage it, backing of the throttle a little bit
lets it engage seamlessly.
You said

At idle TPS supplies 5v to LP solenoid and it drops to 0v very quickly eg before 1000rpm. The first manual conversion I did I ran 3.5v at idle and it dropped to 0v at 800rpm

This is what I found with mine. 0.5 v when disengaged (from idle all the way through the rev range) and upon activation it takes about 6 seconds to reach 23.6 volts. My options of 24 volt power sources either direct from battery or off the accessories circuit actually reads 25.2 v. Is this a problem ?
You said

The computer supplies a pulse signal to the lock up solenoid which is why the reading your guys
are getting is variable. Supplying a constant power supply to the standard solenoid will cause a
reduced life but the reality is you won't notice it as the auto will need an overhaul by then
anyway

Is there anyway around this and why do they have variable feed anyway. Good to hear full pressure comes in at low revs.
PS. Will rig up an extra switch on the dash so can run the lockup clutch either in manual, or normal mode incase someone else uses the truck.
You said

If you want a manual conversion I've worked out the wiring so can help with it.

Thanks darinz - Sounds interesting. please elaborate
What I would love is a stronger lockup clutch which could handle a good workout.

Appreciate everyones help
Cheers

[darinz]

Hi Darinz.
Have been away for a few days so before I left I quickly rigged up a rocker switch on the front of the shifter so I could flick it on and off with my left thumb. Boy, this is definately a must do mod ! - Truck drives way better (Have done some towing and cruising). Very happy
Great keeping it locked up when cruising or when in Drive on windey roads or opt to leave it out when accelerating or need more revs. I realize it is not a strong clutch so tend to nurse it a bit, but manual activation must prolong the clutch life as it's not switching in and out, and when you do engage it, backing of the throttle a little bit
lets it engage seamlessly.
You said

At idle TPS supplies 5v to LP solenoid and it drops to 0v very quickly eg before 1000rpm. The first manual conversion I did I ran 3.5v at idle and it dropped to 0v at 800rpm

This is what I found with mine. 0.5 v when disengaged (from idle all the way through the rev range) and upon activation it takes about 6 seconds to reach 23.6 volts. My options of 24 volt power sources either direct from battery or off the accessories circuit actually reads 25.2 v. Is this a problem ?
You said

The computer supplies a pulse signal to the lock up solenoid which is why the reading your guys
are getting is variable. Supplying a constant power supply to the standard solenoid will cause a
reduced life but the reality is you won't notice it as the auto will need an overhaul by then
anyway

Is there anyway around this and why do they have variable feed anyway. Good to hear full pressure comes in at low revs.
PS. Will rig up an extra switch on the dash so can run the lockup clutch either in manual, or normal mode incase someone else uses the truck.
You said

If you want a manual conversion I've worked out the wiring so can help with it.

Thanks darinz - Sounds interesting. please elaborate
What I would love is a stronger lockup clutch which could handle a good workout.

Appreciate everyones help
Cheers

Starting from the top.
It is about overheating the soleniod. They are designed not to have constant full voltage so supplying it will shorten the life. How much? I don't know.
You can buy a manual lock up kit from Wholesale Automatics but it costs a bit but has had very good reviews.
The manual conversion i did didn't change anything inside the auto, it was just modified wiring. If you want to do anything to the clutch then that is a job for a torque convertor specialist. I've had mine upgraded but in general that means they strengthen the spline as that is the weak point. The rest of my torque convertor (s) have been standard. eg The one that was behind my TD42T (which is going into an even more worked truck very soon) and the current one behind my turboed VH45.
Can you read a wire diagram? While the wiring involved isn't dificult you will need to work a few things out and it will mean wiring in 4 relays to the inhibitor switch. Basically you have 2 shift solenoids, a lock/up and a line pressure solenoid. I didn't worry about the over run solenoid but you could wire that in if you want but I didn't see any need. 1,2 and 3 are selected by the shift ie 1,2, and D. 4th is selected from the power switch and you use a an additional switch (that you already have) for the lock up. The only signal from the TPS that you want is the 0v to 5v signal and I got a 24v to 5v supply to mean the coputer wasn't needed at all. And that is it!
Most of it is just figuring out which colour wire to use and then joining them up. It is several hours work but if you are still keen then I'll give you a hand to sort it out.

[Muzza]

if you are still keen then I'll give you a hand to sort it out.

Thanks for the offer Darinz but at this stage a manual shift is probably a bit more than I need. Just waiting to hear back from Wholesale Automatics about their "Manual Control Lock-Up Unit" 's voltage signal as it looks exactly the same as what Shane has done and what I currently have rigged ?. The Juland "TransLocker" works a bit differently and not really what I want.

Nice pics of your truck - VH45 280rwkw
You must crave power more than Helen Clarke, mind you I think they were using a highly modified version of the VH45 in the US Indy Car series, where it was doing over 550kW!

Thanks Darinz and everyone for all the help and the pics and info from Shane.

[darinz]

Would you believe me if a I said it isn't even tuned for top end power! Still limited to 6000rpm and not using VVT. So once bigger injectors are fitted, it can be retuned with the VVT and increase rev limit to 7500,then it will have somewhere around 300 to 320 rwkw and that is the limit of reliability for the trans. Not sure about torque but by calculation it should be about where my TD42 was with 20psi.
However i have to leran how to use what I've got first!

PS The good thing about having power is you don't have to use it but if you don't have it then there is nothing to use.

[Muzza]

Power is relative to. I once had a 2.4 NA Diesel Hilux and anything is powerfull compared to that !
Update
The price of the Wholesale Automatic Transmissions lockup switch is $195 Aus = Plus $27 Aus postage and handling They say these units run at constant voltage and are reliable doing so. I think they have it so it doesn't fade the radio when switching out but otherwise there is nothing to them, and basically do nothing more than the simple wireing discussed here.
Looks expensive to me !
I put a two way On/On switch in the dash so I can run it in either standard mode ( Auto ) as a safeguard when someone else is driving or Manual mode, and just a small rocker switch on the shifter to lock the clutch in or out when in Manual mode. The rocker switch has room to actually be recessed into the shifter when I get a chance.

Cheers
Murray

[flyingbrick]

With the switch you guys have put in to lock the TC, if you have the TC manually activated, does it still change down a gear (say 4th to 3rd) with a hard prod on the throttle? ie. Can the auto still work with the TC locked?

Yes it will still change down but it is a pretty hard shift!
I've gone a few steps futhur and actually did a complete manual shift conversion on mine. I did it first by removing the computer and replacing it with a series of relays and controlled the line pressure directly from the TPS. This worked pretty.

I have now gone a step furthur than that and have a complete manual valve body for it (from Wholesale Automatics in Melbourne). This is an amazing upgrade as it is basically a clutchless manual now. It runs increased line pressure so has less slippage and better engine braking and also runs cooler. Take into account I have 280kw at the wheels and the auto doesn't overheat at all. Well it hasn't in the past 12 months since it has been going. I can change gear at full throttle on the rev limiter and it is very very smooth. At low revs and no load, well then it is a bit rough!

The biggest problem with a the Safari (and Terrano) auto is the factory oil cooler. As the torque convertor wears, it drops particles and these block the factory cooler due to small (but efficient) passage ways. Once these are blocked that reduces the oil flow to the gear set. This then melts and basically destroys the entire trans. The easy fix is to service and change the filter regulary and get a rebuild done BEFORE it dies as you will save about $1500 to $2000 on the job. ie I got mine rebuilt and upgraded including torque convertor mods and increased clutch pasks etc and it was only $3k.

Oh yeah Nissan electrics suck badly and before you question anything inside the auto, you can almost guarantee it will be a TPS fault or a broken wire! But with the right mods it will reliably handle 600hp (450kw).

I'm very keen for more information on your manual auto setup- scematics or whatever else you could help with- either via here or PM is great

[darinz]

Do you want the cheap electonic version or the upgraded valve body version?
The first is pretty cheap and is basically a rewire of the auto but the second is by far the best option but will cost about AU$1500.
I've still got the 5v supply needed to run the line pressure via the TPS and have the wiring diagrams if interested. The wiring will still need you to do a bit of work you will need to break into the loom to and wire a series of relays. (4 in total) It isn't overly complicated wiring but it isn't a beginers job either. ie We did but then we did the complete custom loom for my current setup.