Gen4 Auto, footwell hot during off-roading.

Hi all, 

Just finished a big trip down Googs Track in South Australia. It is roughly 200km of sand dunes. Didn't get stuck at all in the zook. Overall a 4000km trip, great experience in outback Australia.

Fairly hot weather, lots of low range climbing up some chopped up dunes. Air-con on and fully loaded with wife as well. All together with soft sand yes the Jimmy was working hard (about 12-15L/100km). Has anyone experienced the footwell in the Jimny get really hot? We stopped under a tree for 15 minutes and let it idle. Thermo fan was only occasionally coming on so no engine coolant temp problems. The auto was fine as well. No tranny whining, and didn't labour in a high gear. Footwell, especially touching the transmission tunnel was very hot. On the highway though, back to normal.

I reckon it was just heat soak from high hot air pushed by the thermo fan and a piping hot exhaust, along with very slow speeds. Again, no trouble codes, just a really hot footwell after about 3 hours of crossing dunes in the heat of the day.

So people don't threaten me with automotive abuse, the zook before the trip had fresh oil change with fully synthetic 0w-20 oil. Checked daily, never burnt any oil. I'll change it again when I get back home.

Cheers,
Stephen

We might accuse you of "automatic abuse"...

Automatic transmissions when used off road, especially in sand, have a tendency to run hot, personally I like at the very least a temperature gauge and if/when necessary a transmission cooler.

The TCU on the JB74 does have the ability to report temperature via the OBD port if you have the ability to read the data.

Pull the transmission dipstick (low down on the right side) and take a look at the fluid, does it look or smell burned?

bear in mind that when driving at speed the airflow will cool your transmission and the underside of your car. But while driving slow the heat from your transmission will more easily transfer up into your legs.

While pulling my trailer up steep slow hills during summer, while wearing shorts, i often feel the heat from the transmission tunnel. But as usual i do not mind it much, just turn the AC on feet mode.

(I have a manual.)

agreed if I'm slugging about on the farm with a full trailer it starts to heat soak into the cabin but I have to be doing it all day really to get it warm warm. just doing something one off doesn't give it chance.

Sounds like a very normal heat soak situation. Operating temperature for an automatic transmission is around 80°c, and for an engine it's higher. That's to say, when everything is operating normally those parts are very hot, too hot to touch. If you spend a long time driving at low speeds that heat is going to start warming up the things around it, and the transmission tunnel is just a few cm away from they hot transmission, engine and even hotter exhaust. It's to be expected that the heat will be transmitted into the cabin.
I drive tractors and on some models, when working hard at low speeds, the windscreen gets too hot to touch due to heat soak from the engine!

I was constantly afraid of that a lot of the time. Did a lot of the deep and steep dunes in low range and did the rest in L high range. I'd love to get an auto temp gauge in the future, maybe the Scan gauge. I'll inspect the auto fluid.

Does anyone know when the auto temp idiot light goes on?