Hi team,
I hope you're doing very well...

Just curious and ask you if some of you tried to monitor tranny oil temperature in specific conditions:
- outside 30C / 86 F
- city stand still drive
- my tranny oil is 97C / 205F

I am thinking about to install extra cooler for it...because too hot to me.

BTW: what about Gulf edition? How it is handled for Gulf region?
Thank you
Marek

 

The trans is heated by the engine coolant is the radiator and has zero issues at that temperature with a 200+ mile interval. When I changed my factory fluid out at 202k it was a waste of money....

 

In my question I meant tranny oil not tranny itself. The high temperature is not good for fluid and also for transmission itself. If possible to lower down at least for 10 - 20% it could be great I think...
Marek


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The transmission already has an oil cooler. It is built into the bottom of the radiator.
That prevents the oil from getting hotter than the coolant, which is temperature controlled by the fan & thermostat so can go to 220F/105C.

If you regularly tow or live somewhere that is very hot for much of the year, then you can either fit the towing radiator (it's a bit thicker) or an aftermarket separate transmission fluid cooler.
However, in stock form the LS430 copes fine with hot places like southern USA and the Middle East (45-50C) so Czechia is fine, even if you drive to South Italy or Greece.

 

Hi BigBoomer,
thank you for information.
My idea was initiated the point that more hot more intense to degrade oil and tranny components. So even I am not towing ( and never be with AT ) I start to think about temperature lowering down -> the 85 sounds good to me but not 97

Nevertheless I will keep it like it is. It could be very interesting how many miles / km can LS430 drive with single transmission in Gulf area for example (or south US area) where temperature is always between 30 - 50 C degrees...

Thank you
marek

 

Transmission fluid and engine oil are designed to work at those temperatures as that is normal operating temperature. 175-225F (80-108C).
https://www.motortrend.com/how-to/08...20transmission.

If you regularly drive in temperatures over 40C then I would move to 15W50 or 20W50 engine oil, but the transmission fluid does not need to be changed.

 

I had an external transmission fluid cooler when I had my LS430. It bypassed the cooler integrated into the radiator.

I saw transmission fluid temperatures at about 176F (80C) when driving normally, 194F (90C) when driving aggressively with lots of downshifts. If I sat idle for long enough, the system would heatsoak and plateau at about 204F (96C), the radiator fans would do their job. Sometimes idle temperatures would hit about 212F (100C) if it was a hot enough day with stagnant airflow.
When I towed... yes... towed with the LS430, temperatures would range from 90C to 96C while driving around with a load.

The external transmission cooler increased the amount of time it took for the transmission fluid to heatsoak.
Your temperatures are totally normal.

 

Thank you for your information. Very valuable to me.

As I have mentioned before I would like to extend transmission life till overhaul will be needed and postpone such situation as much as possible.

Thank you again.

Regards
Marek

 

And I already told you that after 200k on FACTORY fluid nothing happened to the fluid or trans and it was as red as new fluid etc....

 

I hear you - I drove a third-generation Toyota 4Runner for a long time and one of the few failure points was the A340F trans cooler setup and temp. Cheap insurance to be aware of the temp and service the trans the way Toyota and Lexus recommend, even if it's for peace of mind.