Thread: Adding an additional auto tranny cooler into TD5

just wondering why everybody seems to want an additional cooler?
have people actually checked to see what temps they are running?
I drag a 2.5t caravan all over oz with my 01 Disco 2 TD5 and whilst driving I constantly monitor both EGT and trans temp. I have fitted a sensor to the oil pipe where it exits the trans on its way to the oil cooler.
Normal oil temp while diving sits pretty steady around 60C (+/- couple of degrees) except when driving through cities with constant stopping and starting at traffic lights where I've seen it rise to 90C one time.
I know when I first got the disco I did an oil change (with the recommended oil) and whilst moving house using one of those enclosed furniture trailers you can hire and transporting all the household goods between Melbourne and Wangarratta I at one stage had to pull over on the side of the road after tackling the Craigieburn hill (northbound) due to the transmission slipping and the smell of burnt oil. Had to wait some time for everything to cool down before I could carefully continue.
When I got back to Melbiourne I drained the oil and, sure enough, it was burnt (both looks and smell) and after a bit of research ended up using Nulon Full Synthetic Multi Vehicle ATF (gold container).
Since mid 2010 I have been travelling around oz using this fluid and have never had a problem. I have changed the fluid twice during this time, not because I needed to... but because I felt I should just in case. On both occassions the drained oil looked as good as new and had not the slightest smell of burning.
So... is there something unique about my TD5 or is it that there may not really be a need to upsize the transmission cooler in the first place

I have fitted a gearbox oil temp sensor between the box & the cooler. The difference in temperature of the oil between the torque converter locked & unlocked is staggering - as much as 40deg on some occasions. Both the engine & gearbox run cooler at 60-80 kmh in 3rd gear locked compared to 4th gear unlocked.

Originally Posted by Milton477

I have fitted a gearbox oil temp sensor between the box & the cooler. The difference in temperature of the oil between the torque converter locked & unlocked is staggering - as much as 40deg on some occasions. Both the engine & gearbox run cooler at 60-80 kmh in 3rd gear locked compared to 4th gear unlocked.

I tried to find to find the thread(s) confirming the flow direction reverses when locking up but couldn't do it this morning. Your temperature change would support flow reversal since one reading would be pre-cooler and the other would be post-cooler.

This is one of the reasons I'm going for an additional cooler instead of monitoring a temp gauge - I'd never be sure that I was getting a hot reading. They're both about the same price and (hopefully) the cooler will improve the situation rather than watching it. I have read about people tapping/gluing a sensor into the sump itself or the fill plug. Not sure I want to go that way.

Personally, I had the warning light come on once a year ago and I have both a rough 1-2 shift and 2-3 flare for 9-odd months now. About to start towing a 2.5t caravan so $150 for a cooler seems pretty darn cheap compared to the rebuild I expect is coming my way soon. Worth a shot.

Include a bottle of Lucas anti shudder trans fix for added insurance . I've been doing this for a few years now on our 99 & 01 D2's with only improvement in shifts and temp the result . .

Makes me happy with my factory looking uprated Trans cooler fitted in the original spot

No extra plumbing complexity and looks close to stock

Regarding the question about need for an additional cooler, after I started towing a 2t van my passenger complained about a lot of heat radiating from the tranny inside the car. I found it was much hotter than normal which made me worried 'altho nothing to that point had malfunctioned. After having a aux cooler kit fitted by MR plus FS fluid I'm much more relaxed and I find the tranny is now just "normal driving" warm when towing so its doing its job.

Originally Posted by Milton477

I have fitted a gearbox oil temp sensor between the box & the cooler. The difference in temperature of the oil between the torque converter locked & unlocked is staggering - as much as 40deg on some occasions. Both the engine & gearbox run cooler at 60-80 kmh in 3rd gear locked compared to 4th gear unlocked.

hi Milton477,
when you say a temp sensor between the box and cooler... where exactly?
because the fluid will start to cool rapidly once it leaves the trans on its way to the cooler. My sensor is at the trans exit before the cooler pipe.

Is there anyone out there who has fitted an additional cooler, who also has a winch fitted?

Pics to share of this or experiences would be much appreciated. I've got a decent sized cooler fitted by the previous owner but it sits smack bang where the winch cradle is in the bar.