auto oil temps

[Handy Andy]

Gidday Gentlemen
Just wanted to post some info for whatever its worth and perhaps it will help someone. I currently tow a van around 2.4 T plus and have for some time been mindful of transmission oil temps. When not towing I can see temps around 75-85 and when towing, see temps of 90-105, I have never had any issues or alarms and regularly use sport mode when towing. I recently purchased a Davis Craig cooler with 10 inch fan and last week pulled the grille out and made up some brackets and fitted it, also wiring up the relay and switch . The original plan was to have an auto shop connect the oil lines but while in there, it all just looked to straight forward so after a couple of coats of looking at, I bit the bullet and did it myself. I haven't towed the van yet, so I don't want to be too cheeky but today I drove from Brisbane to north of Nambour and back after picking some gear up.
While within the Brisbane area (traffic) the temp sat between 60-65, once travelling at 95-100 klm/h
the temp dropped back to 55-56 and sat there. If I came across road works etc where 80klm/h was the rule the temps went back towards 60-65 and as soon as speed was increased beyond 85 klm/h temps went back down to 55-56. I had no reason to switch the fan on at any stage, I'm delighted as I had agonized for some time about getting an aftermarket cooler and I couldn't find any detail on our ever so helpful forum. I cant wait to tow the van to see what the outcome might be there and even if it's half of todays gains, I'll be happy.
Keep up the good work boys
Andy

[rykiel575]

Thanks for the update.


How much extra LV Tranny fluid did you have to put in with the new setup?

I'm sure you are aware but there's a few guides on here and the NW tranny seems a bit finicky.

Gotta be a certain temp, gotta unplug the 'check' level bolt and let oil slightly weep out, then you have the right level check.

[Handy Andy]

transmission cooler

Gidday Rykiel
I've been away for a few days on Fraser and just saw your question.
When I opened the oem lines to the oem additional cooler in front of the radiator, I dropped only minimal oil, probably one maybe two teaspoons, the new cooler once I had installed it had both outlet port and inlet port in the upright position, I removed the plastic port covers which were in place when it was taken from the box, and carefully filled the core till each port was filled to the very top. Just to be certain and with a very clean old style transmission and diff filler the one with a plunger I then forced new fluid through the new cooler just to ensure it was perfectly clean and the oil was forced through into a clear plastic line and into a clean bucket....it was as if new. The cooler core was again topped to full and once the hoses were connected to it I filled them with oil maybe 50 to 100 ml and connected them again with minimal spillage. To date the transmission is as it was prior and I will, before the year is out, have the levels checked by either MM when serviced or an auto shop however there is no present indication of need to do that.
From what I observed, once the engine stops, the oil in the lines will to some extent, drain via gravity back to the box which is lower and hence the loss by spillage is minimal
Andy

[Handy Andy]

transmission cooler

Hey Rykiel
The cooler took about 400 ml plus the 50-100 ml for the lines.
Andy

[m_and_m]

Alternative is a lockup-kit

In the Pajero, you won't see an over-temp transmission oil warning until it reaches 147 degC. After 125 degC the oil starts to degrade, so once the warning light comes on....well...it's all too late.

One way to solve the problem of keeping the trans. oil cool is adding a larger transmission cooler.
It definitely does reduce the transmission oil temperature, however the heat extracted from the new larger cooler then goes into the air-conditioner cooler and the engine radiator. You'll see higher temps on the engine, and less air-cond performance.

Another way to reduce automatic transmission oil temperatures is to stop the cause of the heat at the source....the torque converter.

The slip in the torque converter is the main source of the heat. Lock the torque converter = no more heat causing slippage.

A kit that locks the torque converter eliminates the root cause of the heat, but as a bonus it also improves fuel economy by >10%. ie. the heat generated in the unlocked torque converter is simply the extra fuel burning and causing the heat in the oil.

We've done a lot of testing that backups up the above claims. Using a lockup-kit not only massively reduces transmission temperatures, but also has the benefit of reduced fuel consumption and reduces engine coolant temperatures.

Some of our customers in Northern WA use both solutions (bigger trans. oil cooler and lockup-kit). After all, towing in temperatures >40degC is extreme for any vehicle.
A customer in eastern Oz has since removed the after-market oil cooler, as with the lockup kit also installed the oil is not getting warm enough (go figure!)

See it in a action and check-out the video of the benefits of our lockup-kit here.

[Kellz]

Well...
I had the auto transmission oil temperature warning two times yesterday in short succession while driving my 3.8L petrol SWB out of a canyon climbing 1500m. Not towing. I was in normal drive and 4HLc. No sport mode (manual mode). It was around 40C outside. The engine temp gauge (in the dash) showed dead on same as usual, exact center. Aircon was also running fine.

Once over the mountain with two cooling down stops I had no warnings any more. Way home 3h over motorway at 120km/h eveything back to normal.

Any advice? No mods to the system.

[old Jack]

Well...
I had the auto transmission oil temperature warning two times yesterday in short succession while driving my 3.8L petrol SWB out of a canyon climbing 1500m. Not towing. I was in normal drive and 4HLc. No sport mode (manual mode). It was around 40C outside. The engine temp gauge (in the dash) showed dead on same as usual, exact center. Aircon was also running fine.

Once over the mountain with two cooling down stops I had no warnings any more. Way home 3h over motorway at 120km/h eveything back to normal.

Any advice? No mods to the system.

1500m vertical climb?
Over what distance, 3kms?
How much time taken?

OJ.

[Kellz]

Like 12km gravel/dirt track over maybe 45min. Sometimes flat, sometimes rough & steep.

Also I hear some kind of liquid sound with little bit grinding sound when idling and gently pressing accelerator (park or neutral). I am not amused.

[old Jack]

Jatco V5A5 or Aisin V5AWF?
Jatco has ATF dipstick, Aisin is fully sealed.

OJ.

[Kellz]

It has a dipstick. When the over temp alarm came I checked the level it was fine okay in the "hot" mark. I had a guy change the AT oil. He drained some and refilled 4 or so liter. Dipstick was okay afterwards as well.
Had the engine oil and coolant also changed same time. I just hope I am only low on ATF. It's late. I check tomorrow morning with cold car all three levels again.

[m_and_m]

Well...
I had the auto transmission oil temperature warning two times yesterday in short succession while driving my 3.8L petrol SWB out of a canyon climbing 1500m. Not towing. I was in normal drive and 4HLc. No sport mode (manual mode). It was around 40C outside. The engine temp gauge (in the dash) showed dead on same as usual, exact center. Aircon was also running fine.

Once over the mountain with two cooling down stops I had no warnings any more. Way home 3h over motorway at 120km/h eveything back to normal.

Any advice? No mods to the system.

You say “ No sport mode (manual mode)”
Does this mean you used the transmission DRIVE mode for the climb?
If so, you’ll find you’ve done most of the climb in 3rd gear. This causes a lot of torque converter slippage and the heat. My advice is next time use SPORT mode in 2nd, or 1st gear to reduce the load on the torque converter.

[old Jack]

Would Lockup Mate for Jatco auto in the CRD 2.5 Challenger/Triton 131kW/350Nm work on the 3.8 EFI 3.8 182kW/329Nm engine since they have the same Jatco auto?

Suspect Auto Mate might change gears too early even with offset adjustment at level 10.

Would need to do some more research on gear and diff ratios as well as AT ECU wiring.

OJ.

[Handy Andy]

transmission cooler

Gidday Marshall,
Yes I have your automate on my list, champ. As I haven't, to date, had any issues or seen real high temps I'm probably just playing for now, but I'll no doubt be in touch one day soon. I've watched your video and read as much as I can and I'm very keen.
thanks Andy

[Kellz]

Well, all fluids are fine. ATF is little bit on the higher side, cold and hot.
Still get that gurgling sound initially when going from idling to, let's say 3000rpm. Once I am past the first gurgling then there is nothing (I think so). Even when hot this is still the case. But I think it's only when car is stationary and I accelerate. When the car is rolling / idling in drive D and I press the accelaerator I don't think I hear it (but can be wrong due to higher ambient sound levels from rolling).

Can too high level of ATF make this sound? The ATF on the dipstick is nice and red transparent (new one).

I have no good shops around... The downside of working in the middle-east...

[Handy Andy]

ATF oil

Gidday Kellz
I dont know a lot about the gurgling sound your troubled by but I've read that there was a fuel tank issue that could have fuel moving through baffles that caused a bump/noise. Perhaps a couple of extra litres of fuel might change the outcome, maybe, maybe not.
Andy