Hello from the Bradfordian down under!

Got me a '93 discovery a while back and for the last few weeks I've been getting an overheated engine. Cleaned out my radiator, fixed a split hose, changed my thermostat and engine is running right on target for temperature now.

But, having fixed that, my automatic gear box is overheating. The oil cooler for the auto gb is mounted right on the front of the car, in front of the heat exchanger for the aircon which in turn is in front of the radiator.

I've taken out and cleaned the temperature sensor which is fastened into one of the oil cooler pipes, but the problem still occurs.

It's so frustrating because I can drive at a 100KM's/hour down the freeway (like jetting down the M1) and when I get off and approach home the warning light for the gb flickers on then goes steady red.

I've checked the transmission fluid level and it seems good. The oil is pink and maybe a bit thin looking. But the transmission runs great IMHO, changes well, no great big clunks when selecting D or R. But...

There is a bit of a clunk, but nothing startling, when going in this sequence N->D->N->R. My engine idle is set ok, which is one thing to watch for with a gb clunk.

Am I able, as an amateur to just drop the oil out the gb and replace? Do you guys have a recommended oil to use in a 93 disco? Also, have you heard of/used oil stabilisers? People seem to indicate these help lower temperature a lot in gb's and axles.

What are the risks of overfilling a gb with transmission fluid? What can happen in that situation. I think there is a chance when I topped it up a while back that I may have over done it.

I've owned the car since it has 185,000 KM's and its now got about 197,000. Is it time for a gb oil change? If I try to service it what would I need in terms of servicable parts.

Sorry to write heaps, but I really want to avoid being a sheep in Australia, and getting it lubeless, like a seized engine.

I appreciate everybodies efforts that got this site running and loaded it with so much excellent info. Many thanks!

Chris.
Perth, Australia.

mine was like yours it kept flickering the red light on but everything worked fine...turned out to be the sensor was faulty, theyre dead cheap so maybe worth a shot

Hi i would say the same as kev i would either change the sensor as they do go wrong more than the gearboxes,have you got a digital temp thermometer so you can check the temperature,as said the sensors arnt to expensive so might be a good thing to start with,pink gearbox oil is good brown and really burnt smell is not,ATF does smell a bit burnt anyway,sounds more like a cooler fault than the gearbox at fault hope this helps tiga.