We have had an oil cooler leaking for a long time, Not horrible but making a mess under the truck.
So we finally dug into it.
Not a bad job, just really messy.
Part numbers from IH
1807563C1 o-rings 2 needed 7.82 each
1804414C1 o-rings 2 needed 5.29 each
1831666C1 Flange gasket 1 needed 18.40
1831665C1 flange gasket 1 needed 7.74
Total after tax $55.50
Drain as much oil and antifreeze out of it as you can.
No need to pull the driveshaft, or anything out of the way.
Unplug the block heater.
Pull the oil filter.
2 bolts on the front flange, take a 10MM socket, we used a really long extention and u-joint and did them from standing outside the front tire.
The rear is 3 bolts. Same 10MM socket. Done from underneath the truck.
You have to twist and turn it like a puzzle but it will come out of there without jacking the engine or doing anything else.
Ours was Rusty to the point we are actually worried about the case leaking and not the O-rings, but so far the O-rings have fixed it.
I guess we don't have pics of it apart, but take a dead blow, or a rubber mallet and drive the ends off, they are just pressed on and held on with the O-rings, nothing else to it.
We cleaned up the core and painted it to protect if from rusting farther.
We cleaned the O-ring surfaces inside the head ends.
Be sure and lube up the O-ring when putting it back together and we used the same Dead blow and just beat it back together.
I have read some guys use a press, and some use a ratchet strap. I am way too lazy for that.
Clean the gasket surfaces and bolt it back up in there.
Re fill fluids are you are done. You should do an oil change in case any Antifreeze fell in the oil. We didn't see anything like that, but it is possible.
It is that simple
If the pressure relief falls out it goes back in Spring first.