Auto transmission temperatures

[Roberto]

My 03 TD5 has done about 220kms. I have had a replacement auto transmission for some 10,000kms, and it seems to be working well. However, I have noticed on my rare trips into Melbourne the transmission temperature light comes on when I am travelling slowly in traffic.

The first time it did this I panicked and added ATF (based on my previous adverse experiences). As I was just heading out of town this seemed to fix the problem. But it happened on my next trip into town as well, and I know the level of ATF was above the marker on the dip stick (I have a P38 sump with dip stick fitted to my transmission).

Keen to explore what was going on I fitted a thermocouple to the ATF pipe leaving the transmission.

At low speeds the temperature of ATF rises quite quickly to around 50 degrees. As soon as it changes into 4th it starts to cool off quickly and settles to about 38 degress at 100 kph. Since I've been monitoring temperatures I haven't been able to provoke the hi temp warning light.

Is this normal behaviour? I am thinking of adding a fan cooled additional cooling element (from China for about $100) to keep the temp down at low speeds - any thoughts?

The bottom line is I can't afford to have a transmission fail during heavy dune work in remote locations.

Bob

[PhilipA]

Methinks you have a faulty sensor.

It should only come on at well over 100C .

Those temps you are showing of 50C are really cool and really too cool.
here is another thread

http://www.aulro.com/afvb/discovery-2/160654-auto-trans-operating-temperature-under-load.html

Regards Philip A

[Milton477]

I also had a similar problem some years ago. After an extended beach run, but back on the blacktop just cruising along, the light came on. I stopped & crawled underneath to have a bit of a look. The tranny was hot but not 100 deg hot so I continued. The next morning, the light came on 2 min from home when it couldn't possibly be hot so I had the sensor changed. I haven't seen it since even when my thermocouple sensor on the ATF outlet is showing 105 deg.

Bear in mind that whatever your thermocouple is reading, it's probably 10 deg hotter. I have just had a reconditioned gearbox fitted along with a second cooler which sits in front of the radiator. My temperatures are at around 50 deg in 4th gear at 100 with the torque converter locked. These rise to 70 deg in stop start traffic in moderate temperatures.

[Pedro_The_Swift]

I am thinking of adding a fan cooled additional cooling element (from China for about $100) to keep the temp down at low speeds - any thoughts?

Bob

My first thought would be
China?!?

PWR Performance Products | Transmission Oil Coolers – External Plate Fin (http://www.pwr.com.au/portfolio/external-plate-fin)
use the vertical scroll to find the last cooler.

My second thought would be to check ALL the line connections for tightness/leaks.
The originals have a bad habit of blowing off--

My third (and last folks:D) is, next time you're out in those remote dunes, remember the sites first rule!;)