Your first post may show an internal blocked radiator, the temp difference should show about a 15-degree difference between top and bottom.
The transmission temp gauge won't come off the peg until the oil reaches 150 degrees and hit hot at 270 degrees.
Warm the motor up and then 
TRY TO DO THE TORQE STALL TEST AND WATCH BOTH GAUGES.
It is not a test to check the torque gauge!!!
When the motor gauge reads hot check the top and bottom radiator tanks with your thermometer.
Bob

Hi, greenfieldrider,
As siescat mentioned, the milky oil indicates that water is getting into it somewhere. If my scant memories of powershift D4Ds are correct, probably the most likely place would be the transmission oil cooler/heat exchanger - unless there is an opening to the transmission or torque converter that shouldn't be open.

It'z been forty years since I was even anywhere near wunna these jiggers and so I can't remember if there was any oil level equalising arrangement between the torque convertor and the transmission but some of the early Hough 4wd powershift wheel loaders had a problem with over-heating that was caused by the breather for the torque converter becoming blocked and causing excess fluid build up in the torque converter. Cleaning the breather cured it and IH/Hough eventually put an equalising set-up between the transmission and the torque converter which allowed the fluid to find its own levels.

To the best of my knowledge, the only 'cure' for a leaking transmission oil cooler is a new one.

Unless I am 'mistooken', Cat cooling systems are supposed to be set to 13 PSI relief valve opening. Ditto with radiator caps if they have pressure relief.

Hope this helps.

Just my 0.02.

You're correct bluox, Doh! I was thinking of the times 40 years ago when I was on a open cab D6D winch Cat in freezing weather. I was having to wait on stand-by on an oil field location between loads of equipment arrived for me to help position. I'd lock the brakes in 3rd to raise the ENGINE temp so I could stand in front of the radiator to warm myself up. I somehow confused which gauge would rise first in my previous reply. 
Craig
 

bluox wrote:

Your first post may show an internal blocked radiator, the temp difference should show about a 15-degree difference between top and bottom.
The transmission temp gauge won't come off the peg until the oil reaches 150 degrees and hit hot at 270 degrees.
Warm the motor up and then 
TRY TO DO THE TORQE STALL TEST AND WATCH BOTH GAUGES.
It is not a test to check the torque gauge!!!
When the motor gauge reads hot check the top and bottom radiator tanks with your thermometer.
Bob
 

I‘m a little bit worried that I damage/overheat the brakes or so. I tried it just briefly. How hard should I press the brakes?

I took a look inside the radiator with an inspection camera. Most of the small tubes are covered with some kind of gunk. 3 are accessible enough from the top so that I was able to clean them out with an old dip stick. Probably won’t change much, lol. 

Now I was wondering if anyone ever tried to just remove the top of the radiator and clean it only from
the top?

That way all the small tubes from the core are accessible and I could clean them with the dip stick and after I plug the bottom and top outlet with a plug, I could also use more aggressive chemical stuff to clean the radiator thoroughly…

What do you guys think?

Deas wrote:

Hi, greenfieldrider,
As siescat mentioned, the milky oil indicates that water is getting into it somewhere. If my scant memories of powershift D4Ds are correct, probably the most likely place would be the transmission oil cooler/heat exchanger - unless there is an opening to the transmission or torque converter that shouldn't be open.

It'z been forty years since I was even anywhere near wunna these jiggers and so I can't remember if there was any oil level equalising arrangement between the torque convertor and the transmission but some of the early Hough 4wd powershift wheel loaders had a problem with over-heating that was caused by the breather for the torque converter becoming blocked and causing excess fluid build up in the torque converter. Cleaning the breather cured it and IH/Hough eventually put an equalising set-up between the transmission and the torque converter which allowed the fluid to find its own levels.

To the best of my knowledge, the only 'cure' for a leaking transmission oil cooler is a new one.

Unless I am 'mistooken', Cat cooling systems are supposed to be set to 13 PSI relief valve opening. Ditto with radiator caps if they have pressure relief.

Hope this helps.

Just my 0.02.

I still hope that the milky fluid is from sitting in the rain but you’re probably right… Hope I can find a new-ish transmission oil cooler.

I noticed that there are to dip sticks for some kind of hydraulic/transmission fluid under the seat.
1. A bit more to the left, that one has milky oil in it.
2. A bit more to the right, that one has nice clear amber colored fluid in it.

Any idea which fluid/oil level I check with those dip sticks? I think one of them is the transmission fluid but the other one?

Hi, greenfieldrider.
Like I mentioned in my earlier post, it'z been 40-plus years since I had anything to do with these jiggers, probably even 50 years, and so I will defer to others with more recent knowledge and/or better tech. libraries.

That said, if you can get the top tank off and clean the tubes, you would still need to get that 'gunk' out of the bottom tank to prevent it being circulated around the cooling system and ending up back in the top tank again. Some of it would also likely end up in the transmission oil cooler core.

Others will have better knowledge than mine on this point too but I suspect that it is possible to remove the transmission oil cooler core and check that out without 'major' disassembly of other things.

It might also be a good idea to check the radiator core itself to see if any of it is blocked externally and restricting air flow through the fins.

Just my 0.02.

remove the rad and have it cleaned at the rad service. they have it done while you think about it. and have the right tooling to clean the tubes properly with less risk of damage.

The gauge on the left is for the transmission torque converter and the gauge on the right is for the bevel gear .
The dipstick is who is pulling the gauges.
The torque is in the transmission case.
If the oil cooler leaks it puts oil in the radiator.
You hold the brakes so the tractor won't move it won't hurt anything.
The best way to fix the radiator is take it to a radiator shop, you get back a good leak free unit.
May I suggest you fix one problem before you start shot gunning parts at this tractor you don't need.
Bob

bluox wrote:

The gauge on the left is for the transmission torque converter and the gauge on the right is for the bevel gear .
The dipstick is who is pulling the gauges.
The torque is in the transmission case.
If the oil cooler leaks it puts oil in the radiator.
You hold the brakes so the tractor won't move it won't hurt anything.
The best way to fix the radiator is take it to a radiator shop, you get back a good leak free unit.
May I suggest you fix one problem before you start shot gunning parts at this tractor you don't need.
Bob

Thank you Bob. I will replace the milky transmission fluid tomorrow and also install a new transmission oil filter. 

You are definitely right, shot gunning parts won’t fix it. I will take the radiator out and bring it to a rad shop, hope I can find one here in Canada. 

Thank you everyone for your help so far, I will give you an update as soon as I have the radiator back. Fingers crossed it’s the radiator!

If you go to Cat get screen gasket and O-rings for filter.
You will need 10 us gallons of oil a SAE10W TO-4 spec.
While you're under tractor pull the torque screen,clesn it and see what's in it.
Bob