Toyota prado KZJ78

[prado_boon]

Hey guys, I'm new here and looking to buy a 1993 prado EX (1KZ-TE)

This one is in good condition
It has 280k on the original head (I think?)

My questions are:
1) How can I test if there is head damage without taking it to a mech?
2) The 4WD light only comes on when I push 4WD and Hub Lock buttons together. Ie. it won't light up when just 4WD is selected ?
3) There is a slight wurring noise comming from the rear at 40kph+. I think it might be the diff. What do you guys reckon ?

If I do get it, I was going to:
* put in a new alloy radiator or maybe just flush the factory one? (Done)
* fit a external trans cooler in series before the factory one (Done)
* remove EGR (Done)
* fit larger exhaust from turbo back (2.5") - autobend off shelf item ?
* fit genuine toyota thermostat (Done)
* service/repack viscous fan (Done)
* fit a EGT gauge from pre-turbo (Done)
* Intercooler ?
* Re-oil rear diff
* Chage electric hubs over to manual (Fixed electric hubs)

Thoughts on the above?

I've just sold the challenger and can't wait to get back into the landcruiser world!



Thanks in advance
Tim (chch)

[kbushnz]

Answers in big font... Sorry

Hey guys, I'm new here, I've just sold my challenger and looking to buy a 1993 prado EX (1KZ-TE)

It's in immaculate condition
It has 280k on the original head

My questions are:
1) How can I test if there is head damage without taking it to a mech?
You cant... Can only see if it already has gone by testing water for combustion gasses.
Then a Mech can only do the basics, leak down check of radiator system and compression checks.
2) The 4WD light only comes on when I push 4WD and Hub Lock buttons together. Ie. it won't light up when just 4WD is selected ?
That's how its supposed to work, no 4x4 without the hubs locked.
There are a few threads on here re how it all works....
3) There is a slight wurring noise comming from the rear at 40kph+. I think it might be the diff. What do you guys reckon ?
Could be the diff, may need oil change.. Could also be the transfercase...

If I do get it, I was going to:
* put in a new alloy radiator or maybe just flush the factory one?
* fit a external trans cooler in series before the factory one
* remove EGR
* fit larger exhaust from turbo back (2.5")
* fit genuine toyota thermostat
* service/repack viscous fan
* fit a EGT gauge

Thoughts on the above?

Yip that looks like a good plan...
Again search the forum as its been done may times....

[prado_boon]

Any idea about the 4WD light not coming on without having to select lock hubs as well ?

I haven't had a look, but the fron hubs might be manual...

[kbushnz]

Basically the 4x4 light will only come on when certain conditions are met.
One is the hub button is pushed (even if the hubs were removed) and then either the 4H button is pushed or the lever is moved to 4L.

Its a real simple system....No fuzzy logic in this puppy...

Looking at the photo, it still has the electric hubs unless they have had the oldblue mod done to them with an allen key head which is rotated to operate the hub internally. Hard to tell from that distance.

Word of warning, when you push the 4H button in, it activates the front drive shaft connection in the transfer-case... And it will spin to its hearts content and may prematurely wear out....

[yeti]

is it from a car yard

[prado_boon]

Hi Yeti, no, its a private sale.

Thanks Calvin, thats good to know. So you cannot simply get into 4H by pushing the the 4H button ? Sorry, still a little confused

EDIT: Read up about it... I think I get it now haha thanks
I'm gonna bite the bullet and buy it then get the cooling system re-done...

[oldblue]

To check the hubs; Push the Hub Lock Button and you should hear the electric motors running for approx 3-4 seconds.and with the box in H2 you shouldn't be able to turn the front drive shaft.
At 280K I would check the carbon brushes

[Jerry]

great choice of truck

known faults to look for:
Caps in ECU can melt (fixable)
Head
If auto check trans service history

get rid of electric hubs (oldblues mod or spacers and hubs)

[prado_boon]

Thanks for the tips.

Sorry but what are you referring to when you say ECU caps? Are you meaning the resistors or capacitors on the PCB inside the ECU?

What are the symptoms and fixes ?

Cheers

[IcedJohnno]

Symptoms of the capacitors on the ECU PCB blowing vary from; engine not starting up, to running briefly then stopping with lots of white smoke (fueling issue), to intermittent stops - usually somewhere embarrassing !
The fix is to send the ECU into various good electronic repairers/auto sparkies.
Anything Electronic in Nelson do a very good and well priced repair. They repair about 4 per week.

Regarding Jerry's comments about the front hubs.
Unless you go to a lot of effort to fit factory Aisan components to get a manual hub, you are far better to stay with the factory electric ones. If they don't work, it is likely the brushes are stuffed, or they have been reassembled in a ham fisted manner. This can force the motor further inboard resulting in gears not being able to mesh.
They can be repaired, or Old Blue can create a manual conversion for them.
These hubs are much stronger than the aftermarket ones, AND they also have one less joint (which fret leading to hub failures)

Old Blue has done a Mk 2 version for me, which are still operable via the push button electrics, but also can be engaged via the Allen head capscrew, like his manual only versions.
Only recently received these, and they are still on the waiting list of things to do. However I rate his work and he has been very helpful to me.

[prado_boon]

Cool thanks, I'll be in touch with Oldblue sometime in the near future! You got a bit of a name for yourself! Well done!

Does anyone know where to "obtain" a KZJ78 owners/repair manual ? I can usually "obtain" one, can't can't seem to find one

[kbushnz]

Does anyone know where to "obtain" a KZJ78 owners/repair manual ? I can usually "obtain" one, can't can't seem to find one

Ahh I haven't found one in 10 years....
Nearest one I have is for the LJ70....

[007]

U might want to check, but I think the electric hubs are stronger than the manual. More bolts. If anyone could add.

[oldblue]

Useing your electric hubs converted to manual gives you the strongest fix to your hub problem.
When you fit after market freewheel hubs you will need a conversion ring kit which can be troublesum especially if diff lock are used.

[wjw]

Useing your electric hubs converted to manual gives you the strongest fix to your hub problem.
When you fit after market freewheel hubs you will need a conversion ring kit which can be troublesum especially if diff lock are used.

You only really have two options for the hubs if you plan to do proper wheeling:

1. Have oldblue convert your hubs (<$200 from memory)
2. Replace the front hubs and stubs with LN130?? ones and put on aisin manual hubs ($150-200 aisin hubs, $300 for new hubs and stubs + labour)

The adapter ring will fail, its not a case of it, but when. even without a front locker. I killed the adapter ring on mine in the mud on the hills of otago.

[IcedJohnno]

You only really have two options for the hubs if you plan to do proper wheeling:
1 - (actually 2nd)
2 - (3rd)

Not quite correct Bill
This truck may have perfectly usable electric hubs.
Bla bla "ain't broke, don't fix it" bla bla!

The first true option, is what I have done up until now.
For 150,000 kms, I have used the factory hubs as they were designed, as electically operated ones. I have yet to have had the wires ripped out when 4 by ing, and I often used big chains and throw rocks around the wheel arches when I am typically in deep snow.
I figure, if the wires are to break, it will be when I am already off-road. Thus I will already be in 4wd. No probs! Sure I get to drive home with the front hubs engaged. Big deal! The half shafts, diff and drive shafts are turning. So what, an 80 series has this all the time. With the transfer disengaged, all I am doing is using a miniscle more fuel.

If for some reason that the hubs don't engage when I want them to, like the brushes not contacting well due to the high kms my truck has done, I can still engage the orig type manually. I carry a 12 point in-hex in my socket set that undoes the electric hub outer cap 12 point capscrews. It is not difficult to manually engage the splines and re-install the cap. I also carry a rag for the greasy hands!

[wjw]

You only really have two options for the hubs if you plan to do proper wheeling:
1 - (actually 2nd)
2 - (3rd)

Not quite correct Bill
This truck may have perfectly usable electric hubs.
Bla bla "ain't broke, don't fix it" bla bla!

The first true option, is what I have done up until now.
For 150,000 kms, I have used the factory hubs as they were designed, as electically operated ones. I have yet to have had the wires ripped out when 4 by ing, and I often used big chains and throw rocks around the wheel arches when I am typically in deep snow.
I figure, if the wires are to break, it will be when I am already off-road. Thus I will already be in 4wd. No probs! Sure I get to drive home with the front hubs engaged. Big deal! The half shafts, diff and drive shafts are turning. So what, an 80 series has this all the time. With the transfer disengaged, all I am doing is using a miniscle more fuel.

If for some reason that the hubs don't engage when I want them to, like the brushes not contacting well due to the high kms my truck has done, I can still engage the orig type manually. I carry a 12 point in-hex in my socket set that undoes the electric hub outer cap 12 point capscrews. It is not difficult to manually engage the splines and re-install the cap. I also carry a rag for the greasy hands!

Sorry yes I was assuming stuffed Hubs :-d

[prado_boon]

Fitted trans cooler:


Fitted a egt gauge:


Flushed radiator, fitted new water pump.

[prado_boon]

I have a slight wurring noise coming from what sounds like the rear diff under acceleration. I'm thinking I'll just replace/top up the diff oil first. Thoughts?

Going to fix my electric hub by making some new carbon brushes.

Anyone had issues with the factory sport/custom suspension switch? Seems mine doesn't work, seems to be stuck on sport (it's stiff) thoughts?

Cheers

[kbushnz]

I have a slight wurring noise coming from what sounds like the rear diff under acceleration. I'm thinking I'll just replace/top up the diff oil first. Thoughts?

Yes change oils.. Look for metal in old oil.. Could have a bearing going... Transfercase can do this on output bearing amongst other things.

Going to fix my electric hub by making some new carbon brushes.

Sweet, there is a thread on here somewhere where I posted a link to a site in Japan where this guy made his own...

Anyone had issues with the factory sport/custom suspension switch? Seems mine doesn't work, seems to be stuck on sport (it's stiff) thoughts?

They are probably stuffed (shocks that is) There is a little valve on the top of the shock...
Time for an upgrade !

[IcedJohnno]

My shocks no longer adjust via the switch. The light on the switch stays on whether you switch it either way. The shocks are not stuffed, they still work fine, even at 250k. I think it is an electrical connection fault. I have yet to find one of those round tuits to help me trace the fault!

[prado_boon]

Simple test, get someone to push the sport/custom button and test the wires (at the top of the shock) with a multimeter.

Mine is fine, but the shocks are stuffed - I'll put it on the list of things.

Yeah I'm following that Japanese fella's steps. Already got the brushes, just need to file them down etc. Might even post some pics!

Need to find out where that wurrring noise is coming from, it's hard to tell!! Hope it's not the transfer case.

[prado_boon]

They are probably stuffed (shocks that is) There is a little valve on the top of the shock...
Time for an upgrade !

What does this valve do?

[kbushnz]

It is what is activated when you use that suspension switch ....
It changes the valving in the shock making it feel stiffer or softer..

[prado_boon]

It is what is activated when you use that suspension switch ....
It changes the valving in the shock making it feel stiffer or softer..

I wonder if it's the valve that stuffed...

[kbushnz]

Probably but its all one unit.....

[prado_boon]

Replaced both electric hub carbon brushes. All in good working order now. Doesn't take long. The trick is to use a peice of wire/metal (or a cut allen key...) to fit snugly into the hole to keep the brushes pressed down while you reassemble everything. Without an exact fit you'll never get them pushed down far enough.

[prado_boon]

Next mod: shocks, springs and new bushes! Any suggestions ? OME ?

[madlux]

You could try efs, I use them in my prado, nice ride on and off road.

[juz]

I run Ironman Shocks/Springs in my Prado, real nice ride and well priced.
Terraquip in Chch are the distributors.