KZJ78 Automatic and Torque Converter
Re: KZJ78 Automatic and Torque Converter
With your model Auto you can only lock the Auto in 1st, any other gear has pretty well no hold back. I tow a caravan and use the auto as if it was a manual box. Take your time and use the gears.
"Oldblue" Electric to Manual Hub Conversion's 03 5447586
Re: KZJ78 Automatic and Torque Converter
The light that came on is an temperature warning...
I would suggest that since you are in Africa and the ambient temperature is high during the day that extra cooling is required for the auto...Typical for vehicles that tow a lot also.
Also you might want to check the state of the fluid and if its at the correct levels....
So an oil cooler should be fitted, as big as you can fit.
As for torque converter lock..... The auto is ecu controlled and the torque converter is set to lock in 3rd or OD and in my observations above 70 - 80 kph.
Its not designed to lock at low speeds and high load demands as the friction linings are not very wide and can / will fail...(some people operate it manually with a switch)
It will not lock when in LOW....the ecu will still follow its basic rules.
Also do your hard load off roading in low range....
And steep hill descents in low 1st.... will offer some engine braking but not as much as a manual , probably equivalent to 2nd low in a manual.
For more info on the auto search A340E in google....plenty out there...
I would suggest that since you are in Africa and the ambient temperature is high during the day that extra cooling is required for the auto...Typical for vehicles that tow a lot also.
Also you might want to check the state of the fluid and if its at the correct levels....
So an oil cooler should be fitted, as big as you can fit.
As for torque converter lock..... The auto is ecu controlled and the torque converter is set to lock in 3rd or OD and in my observations above 70 - 80 kph.
Its not designed to lock at low speeds and high load demands as the friction linings are not very wide and can / will fail...(some people operate it manually with a switch)
It will not lock when in LOW....the ecu will still follow its basic rules.
Also do your hard load off roading in low range....
And steep hill descents in low 1st.... will offer some engine braking but not as much as a manual , probably equivalent to 2nd low in a manual.
For more info on the auto search A340E in google....plenty out there...
Cheers Calvin
KZJ78 Landcruiser Prado...
KZJ78 Landcruiser Prado...
Re: KZJ78 Automatic and Torque Converter
if you have cracked a head then i would be pulling the radiator tanks off and give it a clean out. while your at it remove any factory transmission cooler and fit an external cooler.
failure to do that will probably mean another cracked head.
failure to do that will probably mean another cracked head.
Re: KZJ78 Automatic and Torque Converter
you can't lock the fan without putting a bolt through them which is not recommended as you will end up breaking the fan. but they are easy enough to refill and tweak the thermostat so it comes on earlier.
i don't know that model but i'm well used to the surf which runs the same engine and its also prone to over heating.
you need to take the tanks off to flush them properly.
"not fit for purpose" describes most 4x4's made in the last 20 years
i don't know that model but i'm well used to the surf which runs the same engine and its also prone to over heating.
you need to take the tanks off to flush them properly.
"not fit for purpose" describes most 4x4's made in the last 20 years
Re: KZJ78 Automatic and Torque Converter
Just flushing the Radiator sometimes is not good enough, I found my Rad needed the tank removed and the cores roded to remove any scale.
When towing my Van up steep hills I use 1st gear.2000>3000 Rpm
When towing my Van up steep hills I use 1st gear.2000>3000 Rpm
"Oldblue" Electric to Manual Hub Conversion's 03 5447586
Re: KZJ78 Automatic and Torque Converter
The A343F is an A340E with the part time transfer-case....They changed numbers depending on transfer-case options...
I believe you have an underlying problem.
I thrash mine all day lugging 35 inch tyres and the auto is fine....
Albeit not at ambient temps you would get.
Cooling is something worth looking at as suggested already.
I would post your issues to www.ih8mud.com in the 70 series section... They have a few international members and some from africa....
Best of luck sorting it out.
Cheers Calvin
KZJ78 Landcruiser Prado...
KZJ78 Landcruiser Prado...
Re: KZJ78 Automatic and Torque Converter
The issues with your radiator could well solve some of your problems....
But I will concentrate on the auto.....
Fluid level is checked by running the vehicle to its at operating temps...
Park on a flat surface and while it is running with auto in P or N you then check the dip stick. Top up thru dip stick hole as required.
If you check it with no engine running the fluid drains back into the pan and you get a false full reading.... As when you start running the level drops...
Can drop as much as 2 liters...
The OD is electronically controlled and has some rules when it will activate.
One is speed, also trans temp and also engine water temp (from memory)
So if it doesn't activate at all then there are a few things that need checking...
Also the electrical solenoid in the auto can get sticky and or fail.....
Now getting to the auto cooling.
Fluid is passed thru a tube in the bottom tank of the radiator.
This does two things... when the auto fluid is cold it heats it to the same temp as the water... If its too hot it transfers the heat to the radiator...
If your radiator is blocked, damaged, etc etc as you suggest then it could be working real hard to try and not only cool your engine but also your trans....
What I have done is put a trans cooler into that line.
Its put in such away to cool the trans fluid first then into the radiator to either heat it back to normal or take more heat out if really hot....
If you are getting very high ambient temps then adding a cooler but bypassing past the radiator could be worth while....
However it may take longer for the auto fluid to warm up and not go into OD and torque lock....
Now for steep hills....I dont know the terrain you are driving ....
If its tarmac smooth etc etc just dropping down a gear will assist.... You may need to reduce speed and just plod up....not sure what speed you are trying to achieve....
Off road hill work....Low range...less stress on the drive train and engine....
But naturally will be slower... like 40 kph...
Its difficult to imagine without being there....
Some reading for you
http://www.autoshop101.com/
Go to technical articles... heaps in there about the methodology of Toyota's including the auto's....and how they operate....
But I will concentrate on the auto.....
Fluid level is checked by running the vehicle to its at operating temps...
Park on a flat surface and while it is running with auto in P or N you then check the dip stick. Top up thru dip stick hole as required.
If you check it with no engine running the fluid drains back into the pan and you get a false full reading.... As when you start running the level drops...
Can drop as much as 2 liters...
The OD is electronically controlled and has some rules when it will activate.
One is speed, also trans temp and also engine water temp (from memory)
So if it doesn't activate at all then there are a few things that need checking...
Also the electrical solenoid in the auto can get sticky and or fail.....
Now getting to the auto cooling.
Fluid is passed thru a tube in the bottom tank of the radiator.
This does two things... when the auto fluid is cold it heats it to the same temp as the water... If its too hot it transfers the heat to the radiator...
If your radiator is blocked, damaged, etc etc as you suggest then it could be working real hard to try and not only cool your engine but also your trans....
What I have done is put a trans cooler into that line.
Its put in such away to cool the trans fluid first then into the radiator to either heat it back to normal or take more heat out if really hot....
If you are getting very high ambient temps then adding a cooler but bypassing past the radiator could be worth while....
However it may take longer for the auto fluid to warm up and not go into OD and torque lock....
Now for steep hills....I dont know the terrain you are driving ....
If its tarmac smooth etc etc just dropping down a gear will assist.... You may need to reduce speed and just plod up....not sure what speed you are trying to achieve....
Off road hill work....Low range...less stress on the drive train and engine....
But naturally will be slower... like 40 kph...
Its difficult to imagine without being there....
Some reading for you
http://www.autoshop101.com/
Go to technical articles... heaps in there about the methodology of Toyota's including the auto's....and how they operate....
Cheers Calvin
KZJ78 Landcruiser Prado...
KZJ78 Landcruiser Prado...
Re: KZJ78 Automatic and Torque Converter
theres two problems with the transmission cooler in the bottom tank setup.
on some models the cooler restricts the flow out of the radiator and that the heat from the transmission heats the water back up just before it goes back into the engine. so your trying to cool the engine with hot water.
while maintaining gearbox temp is important i doubt you will ever have problems of it being to cold.
if you can fit a thermostat to the transmission line. that will bypass the cooler when its to cold.
on some models the cooler restricts the flow out of the radiator and that the heat from the transmission heats the water back up just before it goes back into the engine. so your trying to cool the engine with hot water.
while maintaining gearbox temp is important i doubt you will ever have problems of it being to cold.
if you can fit a thermostat to the transmission line. that will bypass the cooler when its to cold.
Re: KZJ78 Automatic and Torque Converter
sorry i don't know much on those.
the old trick with the surfs was to use the radiator for the manual version which dosen't have the trans cooler.
the old trick with the surfs was to use the radiator for the manual version which dosen't have the trans cooler.
Re: KZJ78 Automatic and Torque Converter
MikePrado wrote:Hi guys,
Questions:
1. How much fluid is in the gearbox when full? I want to know how much impact 1.5 litres would be and whether this would cause the overheat light to show.
2. Will mixing different brands of transmission fluid cause a problem? I couldn't contact my original mechanic so couldn't find out which fluid he used.
The whole system in mine holds in excess of 10 litres. More closer to 15..
The pan holds about 3.5 to 4 litres...
The rest is in the box and plumbing and torque converter...
So 1.5 litres might have an impact. Also you check it while the engine is running, at operating temp....and in N or park....
As for mixing brands... I try not too but realistically they should be compatible.... Even the synthetic stuff says its compatible with std ATF fluid...
Cheers Calvin
KZJ78 Landcruiser Prado...
KZJ78 Landcruiser Prado...