Offroad-Express

Hi Guys

My Terrano has the typical auto trans problem...

Under load ie goin steep uphill, the engine temp goes through the roof

Radiator is in good nick and I have already flushed the coolant and replaced the thermostat

So im going to install an aftermarket oil trans cooler mounted infront of the radiator for max airflow, question is

Do I run the cooler inline with the factor cooler in the radiator or is it better to bypass the factory cooler altogether?

Cheers
Leon

i hazard the theory of go inline.. cant have too much cooling on a trans unit..

Yeah i was thinking that too, then read this

http://en.wikipedia.org/wiki/Nissan_Pathfinder

"Nissan techs generally recommend that the stock cooler in the radiator not be used at all."

I recall Toyota having problems with this (could be wrong) and it turned out the oil cooler in the radiator blocked the water flow out of the radiator. Poor design. Maybe its the same for you Nissan guys too.

it only stands to reason that havin the trans cooling lines go through the radiator will take up extra area/volume where the water could have been.. put in a seperate trans cooler on the front of a radiator that isnt using the dual core type set up..

Anyone actually done this install? What did you do, what worked what didnt?

Thanks for the replies so far

Hey mate,

Good call running aftermarket cooler for the trans,

Word on the street is run it completely independent to the original as the original is prone to collecting sludge and blocking up. Have you checked your auto oil? Is it still a nice red and sweet smelling?

Good luck and have fun!

Sketchy_Racer wrote:Hey mate,

Good call running aftermarket cooler for the trans,

Word on the street is run it completely independent to the original as the original is prone to collecting sludge and blocking up. Have you checked your auto oil? Is it still a nice red and sweet smelling?

Good luck and have fun!

Cheers for that, exactley what is was thinking, oils still good but im gonna replace it anyways.

Right next question, if im lying under the truck and lookin at the oil lines in the bottom of the radiator, whats the inline and whats the return line???

Cheers

Bonus wrote:

Sketchy_Racer wrote:Hey mate,

Good call running aftermarket cooler for the trans,

Word on the street is run it completely independent to the original as the original is prone to collecting sludge and blocking up. Have you checked your auto oil? Is it still a nice red and sweet smelling?

Good luck and have fun!

Cheers for that, exactley what is was thinking, oils still good but im gonna replace it anyways.

Right next question, if im lying under the truck and lookin at the oil lines in the bottom of the radiator, whats the inline and whats the return line???

Cheers

I don't know witch is witch, i'm not sure if it matters.
Sounds like you're on the right track. Using the original cooler makes no sense, as if the engine temp is going up too high it can have the opposite effect on the trans fluid and even cause it to rise. Ambiant air temp is always cooler than the engine coolant.
If you are towing, the recomendation would be to get the biggest cooler "shoe horned" in there you can.
If you are going to change the fluid, best to use one of those machines that removes the old fluid and flushes the whole trans including the touque convertor with new fluid while it is running. Did that on a mates R50, was like a new trans
At least with a separate cooler you can see if the engine is causing the rise in temp would be a bummer if the trans was not the cause.

Cheers,
Simon.

in my experience it doesnt matter what way you have the lines around, as its just completing the loop.

Cheers Daniel

Bonus wrote:Anyone actually done this install? What did you do, what worked what didnt?

Thanks for the replies so far

I have an after market cooler on my 95 D21 and it is in line with the stock cooler.
It is placed outside the front of the main radiator in the top left corner as you look at the truck.
The Pathfinder issues are with the petrol engines i believe, seems diesels have a different radiator from my understanding.
Anyway I had my cooler professionally fitted by the auto trans shop. They recommended to put it in line with the factory one. There is a hack you can do with a resistor in the wiring loom, had mine done last week, that stops the torque converter disengaging with the cooler oil from the new rad, I will look at mine in the wknd and try to figure out where they put it and the resistance.
Apparently it is a common fix.

In some Toyota Auto's the out side is labeled P (pumped) & return T
no idea if Nissan is the same or not.

It dosnt matter which way you put the lines on it will still work.
I did mine and the temp over the desert road pulling a trailer droped big time.

On my ol' Terrano I used to get real bad heat coming up into the truck from round the hand brake - figured it was the gearbox, so all I did was pull out the factory trans cooler that sits infront of the radiator and fit a new bigger 1 that was the size of an A4 peice of paper it costed $80 from memory got it from BNT, it only took me 20 mins to do, just undid the two hose clips swapped them and that was it, and I never had any gear box heat ever again even fully loaded going up mountant access roads- money well spent.

As for the engine tempt gauage it was a never ending nightmare for me, even on a small hill it would skyrocket, typically by the time you get down the other side it had come right again. I spent too much money trying to fix it, New radiator, theromstat, water pump, got compression tests done, all made a small difference but never fixed it. In the end I gave up and ignored it; did 60,000kms never had any problems and it was still running strong when I sold it.

thanks guys for all the info, appreciate it

The problem with the factory cooler is the passageways are too small and as the torque convertor linings wear they block these passages. Once blocked this restricts the flow to the gear set and causes extra wear. When completely blocked the entire trans melts and you need to basically through everything away.
So keep the factory cooler inline as your own peril.

It is very important to ensure the fluids flows in the bottom of the trans cooler and out the top. The reason is so the cooler get completely full and actually works. If the entry is the top then alot of the time the cooler won't be full of fluid as it will run back to the sump before the cooler is full.

All 4x4 Nissan auto's from the 80's, 90 and ealry 00's are basically the same apart from size. Safari and Terrano share the same pump bolt patterns (and so can share bell housings) and the valve bodies are the same. The only real differences are the size of gears sets.

kiwipete wrote:

Bonus wrote:Anyone actually done this install? What did you do, what worked what didnt?

Thanks for the replies so far

I have an after market cooler on my 95 D21 and it is in line with the stock cooler.
It is placed outside the front of the main radiator in the top left corner as you look at the truck.
The Pathfinder issues are with the petrol engines i believe, seems diesels have a different radiator from my understanding.
Anyway I had my cooler professionally fitted by the auto trans shop. They recommended to put it in line with the factory one. There is a hack you can do with a resistor in the wiring loom, had mine done last week, that stops the torque converter disengaging with the cooler oil from the new rad, I will look at mine in the wknd and try to figure out where they put it and the resistance.
Apparently it is a common fix.

Here is the resistor mod they did to my wiring loom.
It is a 100ohm resistor, the pictures should explain it all.

Has anyone got a photo showing how they fitted their cooler?

Mine is fitted with the outlet and the inlet both faceing down and mounted to the raditor with plastic mounts supplyed by the maker that go through the raditor and has locking mounts cliped on after passing through the trans cooler.
I have mounted it on the left hand side as you look at the raditor from the front of the vehicle.
I will endevor to pull my grill n get a shot for you but it wont be today.

Long,
Everything I have read about fitting coolers says that the way you have fitted yours it will fill with air,
the inlet has to be lower than the outlet.
Les.

Well its been that way for over 18 months now with no worrys at all

Long,
Have you got an air/con condenser fitted?
Les.

long wrote:Well its been that way for over 18 months now with no worrys at all

It is really simple.
It isn't working properly as it isn't filling up. The only thing causing it to fill up is the restriction in the outlet.
What temperature is your auto running at? Do you have a gauge to be able to say it is working or are you basing this upon it feeling OK?
Auto's are really simple. Keep them cool and they'll last a long time. Let them get hot and they are on a VERY short path to failure.
In your case it seems silly not to spin the cooler 90* and have it work 100% and increase life of your auto.

No Les i dumped that ages ago

Dr Rocket wrote:Long,
Have you got an air/con condenser fitted?
Les.