Auto transmission coolers. Spoke to Castrol today (1 Viewer)

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Feb 3, 2011
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Location
Northern Territory Outback Australia
I was going to get one for my 80 for when we do our trip around Australia towing a van around, but my friendly Castrol man has me thinking otherwise, and I'll tell you why.

He recommends I put a high temp synthetic in such as transmax-II, reason being. oil coolers will cause the trans to run at a lower temp than it's meant to, which isn't good and chances are I will not be heating the oil beyond it's spec and even if I do go beyond the limit, check it weekly for colour and smell, 'if' it is smelling burnt either change it more frequently, or add a cooler (last resort)

Just wanted to share.
Thanks.
 
You don't have a stock tranny cooler?
 
No, not that I know of?
I believe I have an oil cooler next to radiator but believe it's for the engine. But I've been known to be wrong?..
 
US spec is a tranny cooler in the radiator, and another in front of the condenser. I suppose it might be different in AUS, but you might want to take a look.
 
Thanks Spike, will look into it.
 
The hdj81 doesn't have a tranny cooler my suggestion is to get one. That tranny runs hot even without towing. Especially if your going up and down hills.
 
Thanks Kernal. Heres what they said


Thank you for contacting Australia's Largest 4 Wheel Drive Automatic
Transmission Company.

You do not need a bigger oil cooler because your Land Cruiser already has a
very good cooler on it already. We do however have the following options
available to improve reliability and towing.

Please take the time to look at all the web links below and the attachments
above.

Options:
The cost of our Heavy Duty Recalibrated Nomad A442F Valve Body is $895 inc
gst "Change Over"
Wholesale Automatic Transmissions
 
I've never heard anyone suggest someone with a large SUV like an 80 not run a tranny cooler. What was the Castrol guy smoking.... it's just extra insurance.
 
If I am correct the PO has a 1fz, so you already have a factory tranny cooler.
I would just monitor your tranny fluid and temps and see if you really need an extra cooler.
 
Does anyone have photo's of the tran cooler? Also does the oil pipe run through thte bottom of the radiator?

I have a UK spec and it does not have an extra oil cooler but I do have tran temp issues.

What oil cooler should I put on, and how must the connections run

1. from tran to New oil cooler to radiator back to gearbox?
2. from tran to radiator to new oil cooler back to tran?
 
US spec is a tranny cooler in the radiator, and another in front of the condenser. I suppose it might be different in AUS, but you might want to take a look.
So do you lose that tranny cooler in the radiator when you go with an aftermarket replacement radiator?
 
IIRC the heat exchanger in the radiator is a transmission fluid "Warmer" and the external heat exchanger would be the transmission fluid "Cooler".
 
The correct aftermarket radiator should have a cooler built into the bottom tank. IIRC that "cooler" is more of a temperature modifier, it's meant to get the transmission up to operating temp quickly by tapping heat from the engine cooling system. Then the transmission cooler/radiator located in front of the AC condensor is meant to keep the ATF at a relatively constant temp, AFAIK.

Edit: Yoopercharged types faster than I do
 
So do you lose that tranny cooler in the radiator when you go with an aftermarket replacement radiator?

Some have it, some don't. You'll need to research and see if it does or not.

IIRC the heat exchanger in the radiator is a transmission fluid "Warmer" and the external heat exchanger would be the transmission fluid "Cooler".

Yes and no.

You are correct that it assists in warming up the tranny fluid on cold days. However, once it's up to temp, it does assist in cooling.

So the internal tranny cooler is actually both. The external one, however, is purely a cooler.
 
You sould always run a bypass thermostat that only allows fluid to run to the cooler passed a certain temp. Earls makes one. I'm sure others do as well.
 
The simple way to run an auxiliary cooler is to plumb it in line BEFORE the heat exchanger in the radiator. That way, if it overcools on a cold morning, the heat exchanger will bring the oil temp back up to spec. And hot oil will cool down a fair bit before hitting the heat exchanger so that you have less chance of overloading the heat exchanger.

The new 200 series has a thermostat valve in the cooler fittings. Hot fluid goes to the air-oil cooler, cold oil goes to the water-oil heat exchanger.
 
So do you lose that tranny cooler in the radiator when you go with an aftermarket replacement radiator?

If you did, you'd have two hoses in your hand with nothing to attach them to.
 
I can't believe this one's come up again!

FWIW, I also had a reply from a pro trans cooler install guy some time back who said that the 80'd already have a great transmission cooler and theres no real need to replace it, although he still offered me the expensive convesion mods. Sounds honest to me, otherwise he could have lied and told me I needed one.
 
Did you ever locate your tranny cooler?
 

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