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Diesel Boy

Cool & Easy Auto Tranny Mod!

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How's this:

 

Do you hate the way lock up works on your auto box??

All ways in and out at a certain speed etc?

 

Well i just got my whole tranny rebuilt, new everything ($$$$$$ Im broke now)

 

I still had the lock up problem that was really really starting to make me hate the whole vehicle!!!!

 

So i rang the place that did the rebuild and asked about a trick i had heard of.

 

The trick was to put the lock up solenoid on a manual switch, that would allow it to work as normal, then flick the switch and it wouldn't come in at all.

 

What i found out was that it was a five minute job, that required a simple accesory on/off switch, some speaker wire and a soldering iron or connector block.

 

Mount the switch in the cab some where convinient, run the wires through to the engine bay on the battery side.

Between the battery and the firewall there should be a loom with a redish brown plug. Once you have found that plug, find the only blue wire in the plug, cut it, solder the switch to the two cut ends and there you have it, a manual lock up switch.

Simple huh.

Photos to follow................

Cheers,

Pete.

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Guest 95PathDN

Ok, this is gonna be a real amateur question, but what do you mean "lock up?"

I guess I haven't experienced this or I'd know what you mean.

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No No, not a stupid question at all!!

Think of a manual. 1,2,3,4,5 gears.

Your auto has 1,2,D and over drive.

In over drive you have two stages. The first is overdrive. The second stage is lock up. That means the torque convertor (thing that takes the drive from the engine to the gear box, in place of the clutch in a manual)

has its own special clutch that is opperated by the computer.

Just quickly, there is always a loss of power in the torque convertor due to it being a fluid coupling, about 90% power transfer is its best apparently.

The lock up clutch stops this loss of power by locking the two parts of the torque convertor together.

The problem is that you have no control over it. And it can be a real pain at certain speeds and in certain situations. Like you wanna pull out to pass, so you put your foot down, it either struggles away in 5th (lock up) or drops to 3rd and screams, whe4n all you needed was 4th (overdrive). Same on hills.

By doing this simple mod you can control what it does a lot better.

Basically it allows you to control 5th gear.

(why didn't i just say that in the first place?)

Sound good???????

Cheers,

Peter.

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Guest 95PathDN

Sounds great. That makes sense I think I can picture that happening when I'm driving. Smart guy Diesel Boy. By the way ya already had my vote for truck of month. Nice rig!

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so I guess this fixes all of your tranny problems including the power switch? What did they find there or could they not tell what was wrong?

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Thanks for all the help first of all!!!!

 

They didn't find anything wrong at all. Mechanically or electrically. (nothing that would effect the power mode i mean)they suggested perhaps it was the way the computer was set up. There are apparently about three types of set up that Nissan tried over the various years.

 

The switch is better than any power mode thats for sure. Its like having a true 5th gear!!!

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Would like more details on trans mod. The red plug you mentioned, is that in a group of 4 (3 grey and 1brown/red) between the battery and brake fluid reservoir?

If so is it the blue wire with black trace?? It's amazing how many blue wires you can find when you need to cut one?

Also can you explain the operation of the power switch that is situated on the dash next to steering column. Does the trans mod switch affect this power switch?

Are you aware of any problems that would occur if you kept the lockup disengaged for any length of time?

Sorry for all the questions!

Thanks!

:beer:

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Also can you explain the operation of the power switch that is situated on the dash next to steering column. Does the trans mod switch affect this power switch?

 

Power switch changes the transmission shift points, causes it to rev higher for better performance. The switch would not affect it.

 

Are you aware of any problems that would occur if you kept the lockup disengaged for any length of time?

 

Your tranny would over heat and you might ruin your torque converter.

Edited by RedPath88
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Interesting!!!!

Where did you get that from???

I dissagree with that last one about over heating!!!!!!

Mainly for the reason that a reputible Auto trans specialist recommended it of you do a lot of heavy towing on the road like towing a boat or trailer.

He said and i know from being observant that it is a very common modification to pathfinders/Terrano's and Safari's.

Im quite happy that it won't cause it to over heat, its up to personal choice.

I think that the constant engaging and dissengaging of the lock up clutch would create far more heat then fluid being pumped around the torque convertor.

Its just not logical that it can over heat!!!!

Photo's tomorrow i promise!!!

 

Lock up doesn't normally work in 1 - D so surely it would over heat in these gears to??

But it doesn't.

 

An interesting thing is that after a bit of testing it seems that it plays tricks on the computer, and you have to switch off and reset to get lock up again.

As far as i can tell, if you have lock up switched of, then kick down, the next time you shift to overdrive you can't get lock up. Just means you have to use the hold switch so you don't accidentally kick down!!!

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Buzz, the photo's should hopefully explain all the questions you asked, was going to take them last night and post today but the Camera at work was booked out before i got to it. Its such a good one its worth waiting for!!!!

Pete.

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Location of red/brown plug.

Its the bottom plug. Hope fully its obvious!!!

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The brown wire you can see is soldered to the only blue wire on the plug and runs straight to the switch.

It may be a blue wire with a black strip, but still the only blue wire on the plug.

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Difficult getting a good photo of the plug in place!!

Tryed to pull the plug of so i could get a photo of the wire but it wasn't going to let me!!!

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Right. An indepth discussion of how the modification performs.

 

In most ways it does exactly what i wanted it to do.

You drive completely as normal with the lock up switched on. Thats good in its self as you haven't lost any thing by doing it.

 

If you then turn the lock up off, you get 1 - D plus over drive. Thats good as well. Makes climbing hills alot quicker!!! And winding roads through gorges alot smoother!!

 

You have lock up switched of, then you hit a nice fast piece of road, flick lock back on and you can cruise. Want to pass? turn lock up off and boot it!!

 

This is were it gets tricky. I usually use the hold switch on hills and when over taking to stop it kicking down to 3rd and reving (being a diesel revs = noise and almost zero accelleration). In stead using the hold switch you can floor the b1tch and it'l use all that wonderfull torque. Thats were being able to get O.D with out lock up is so great. You can really make her work, with out having to make her rev, which is how you drive a diesel.

Before i put the lock up switch in you could use the hold switch and between 60 and 100km/h it would stay in O.D, flicking out of lock up as as you dropped past 80 mark, but only if you had the pedal down passed the point where it actuates the kick down switch. As soon as you crept over 80 it would lock up again, then your speed would reduce again because the gear was to high for the hill, drop back past 80 and come out of lock up. And so on and so on.

 

SOOOO, with this switch you can click hold, click lock up off, floor it and fly up the same hill at 120km/h. I was amazed, my partner asked what could SHE do to make me grin like that :P

 

After a bit of messing around while driving on long trips, i noticed that if you have lock up switched of and kick down for what ever reason, the next time you go to turn lock up back on it isn't there. For some reason the computer reads an error and disables it. Fair enough. Its all back to normal next time you start the vehicle.

 

This is how i use it now:

Normal driving leave lock up switched on.

As lock up is only a pain in the a$$ in situations like i mentioned before, where i would normally be using the hold switch, i now still use hold but can control what the computer does with lock up.

I also keep the lock up off all the time when running the Centipedes, they really effect the gearing!!!

I have yet to ring up the Trans shop to see if there is a way round this kick down thing. I doubt it though.

 

The switch has no bearing on any of the normal functions on the trans other than this little trick it plays for the unwary!!

Cheers,

Pete.

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Guest drunken_rice

ok im slightly confused on this mod... are you cutting the light blue or the dark blue or the light blue wire??? and are you cutting the wire in half and connecting the speaker wire to both ends of the cut blue wire???? is that what your doing??? since i can't see exactly what you did or where the speaker wire is connected its really hard to understand or see what ur doing.... im just worried i'll mess up so i wanna get it right if i do this... thnx all

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You would be cutting the blue wire, then connecting each cut end to the separate end of two more wires. Speaker wire was used for simplicity's sake because it is already made of two separate wires. The ends of the speaker wire are run into the cab to a switch, where they are connected to the input and output terminals of the switch. It really doesn't matter which end goes where on the back of the switch. If it appears to work backward, switch the wires around on the back and it will work with the switch in the opposite position.

 

It's a simple circuit interrupt, same as any wall switch in your house. You're interrupting the path of the circuit when the switch is open, and letting it run as normal with the switch closed.

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well then would i beable to get my foglights to run without the headlights??

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Well we were on the subject of circuit interrupting and splitting so i thought id just throw that in there sly

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