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I have the 8 speed D4 & have towed 2.8 tons of van for around 80k Km. The Torque Converter is mostly locked.
I have watched the transmission temperature on GAP IID for most of that distance & it rarely reaches 100 deg. It sits at around 90 deg.
Wouldn't bother with an additional cooler on an 8 speed.
I didn’t know that. Thanks.Quote:
Originally Posted by gavinwibrow
Would anyone know how hard an extra cooler would be to install on an 8 speed? I haven’t done much mechanical on the D4 but I did everything mechanical on the D2
Two options,, in the grill or underneath..
fitting should be well within your grasp..[wink11]
Another option could be a dash mounted gearbox temp gauge. The mechanic who serviced our D4 recently mentioned a kit for the D4 with IIRC several critical temp readouts permanently visible.
I guess the negative of that idea is it's no help if it's stinking hot and you have to get to a destination.
I will be fitting one of the overheat alarms to mine. These double up as a temp guage and will save your engine and gearbox if losing fluid and overheating etc.
After years of towing with an auto i always use the gear stick when in hills and working hard. A lower gear and a few revs will reduce the overheating of transmissions. In the old days it was recomended not to use overdrive when towing.
If it is really hot weather reduce your speed and save your vehicle and fuel bill.
Have you had your gearbox serviced and the oil flushed and changed ? I will get this done to mine before heading out with the caravan next
Ian
Bittern
The D4 already has an overheat alert.
Hot weather and speed don’t correlate directly.
Hot weather and LOAD do.
I see many a Shed Dragger over here in 43°+ towing and wonder why. Just set up somewhere, crack a can and relax.
I'll be honest that I haven't read this thread in it's entirety. But thought I'd share a few thoughts:
The GAP Diagnostics IID Tool is capable of displaying the automatic transmission temperatures (this is used when replacing the fluid as it's meant to be at a certain operating temperature for the final refill - 50*C or so if I recall correctly). Drive around and monitor it to see what temperatures your seeing - this should be your guide as to if you need additional cooling or not.
Then have a read of Automatic Transmissions at < Transmission Oil > - this website is recommended by Ashcroft Transmissions (they recommended it on their website at Ashcroft Transmissions ), a mob in the UK that seem to know a bit about the ZF gearboxes. The key points of this are:
There is a minimum operating temperature (65.5*C) and it is possible to overcool - i.e. cooler is not always better. Running for extended periods below this will also cause additional wear and tear.
Ideal operating range is 79.5 - 93.3*C
There is a maximum operating temperature for short bursts (135*C)
And a maximum (149.9*C), after which internal damage begins to occur.
So using this data above and your IID Tool to see your current temperatures you should be able to determine if additional cooling is needed and/or beneficial - thus answering your own question.
Also I suggest noting the guidance of the table that provides a correlation between the operating temperature and length of time and service live of the ATF. Perhaps if your in the upper end of the safe range then the solution is rather to just replace your ATF more regularly rather than fitting a second cooler.
A Scanguage 11 will give you auto oil temp as well as others. (engine coolant, voltage, fuel consumption, inlet air temp, etc)Quote:
Originally Posted by Mike.C
At around $250 it may be your cheapest option.
John, when you get it all sussed (including for a 2.7L 6 speed option[bigwhistle]) I'm sure you will post here[happycry]Quote:
Originally Posted by John_D4
On this trip, I plan to again post readings of coolant, engine oil and ATF temps pulling the brick. I'm very much inclined towards an AFT cooler as stage 1.
Cheers Gavin
I put a unit in front of the rads behind the grille. It is plumbed in series (and after) the cooler in the engine cooling radiator.
Its about 280mm x 200mm square x 19mm thick. PWR model PWO0527 with 3/8 barbs. ($119) plus a few brass barbed connectors and some dear-as-poison 12mm? transmission hose to graft it in (the tranny cooling line hose in the Disco is bigger than you expect). I think the 400mm piece of hose was $38! (less than $200 bucks all up)
I don't think there is ever an issue of the auto transmission fluid being "too cool" because the engine cooling radiator coolant temp is generally fairly high anyhow. The brass coupling from the rad to the secondary cooler gets friggin hot (that's a technical term for some temperature between 60°C and 100°C) and the return line coupling (to the tranny) is significantly cooler - so its doing something, which can only help?
Interesting to note, when the aircon is turned on, put your hand on the aircon condenser and note how hot this component gets with the air on. This warm/hot air is then being drawn through the engine cooling radiator. Our towing regime is to turn the aircon off when climbing any range of significance, and turn it back on when going down the other side. The tranny temps can get very hot very quickly when towing up a range, and once the mass of the tranny is hot, it takes a lot of light load driving and assistance from the tranny cooler to bring the temps down again. The tranny is a large metallic mass of a very hot casing and gears and only 9.5 litres of tranny fluid (as a coolant) doesn't seem enough to move this heat when she's crying out for a rest.
I fail to see how adding a cooler is a "bad" thing.
I will take some photos in the light tomorrow of my install and post them up as it might help someone who wants a small project.
Ok - today is now tomorrow and I have taken some photos in the effort to show how I did it. Hopefully it might help someone with the project. There aren't many photos of this around the web that I could find. Photos show purchased 1/2 inch blue transmission fluid hose because the barbs on the back or the radiator are half-inch (12mm) where the hose supplied with the cooler are 3/8 (10mm ) and most vehicles seem to be 3/8 size. Get some barbed brass tails to convert the 1/2 inch to 3/8 inch (made up from parts on the rack at Repco, photo for illustrative purposes only), some good quality hose clamps, some bracketry and stainless steel bolts and nuts to affix the shebang to the magnesium hood latch panel cross braces (this stuff drills really weird - like the drill swarf is these really light whisky flakes that float in the breeze).
And I cannot stress enough - check for leaks and then check for leaks. The next day and every week thereafter - check for leaks. A rebuilt transmission in these things is not cheap [smilebigeye]
Matti