955L Torque converter

Need to snag "Bob/Ont" on this one😊 😊
Usual causes of torque overheating are excessive internal clearances, cooler issues which you have addressed and excessive oil (drag) in the torque converter housing. Check your scavenge pump.
Sorry, I only have clearance specs for the earlier 955 (60A) model.

The inlet relief valve has no bearing on overheat problems, it is only there to prevent blowing the T/C apart when the oil is cold, you need to check the outlet relief pressure, lube pressure and the temperature drop across the cooler, then you will be able to get a better idea of what is going wrong.

I figured it out. I put all new bearings in it, and couln't find anything that was excessively worn. When I went to install the rear bearing on the shaft, I realized that the seal ring carrier fit very loosly on the shaft. This would allow the oil to leak into the sump as opposed to go to the cooler.
It appears to be a fairly new aftermarket shaft, that was machined only for the bearing, and was never built for the carrier, however, the snap ring groove was in the right place.
A little time on the lathe produced a bushing to correct the problem and I placed it using bearing mount. We'll see tomorrow how it works.

That's some good sleuth work😊 😊
Could very well be the problem.
From your description the 955H (60A) sounds about the same as the "L" arrangement so I am posting the info I have.....kinda fuzzy...hope you can read it.

When you get it together, come on back with the pump pressure at high and low idle with hot oil.
Later Bob

Just reread everything DD, the seal ring can cause a problem but if it was really bad like one I tested with the ring missing the Torque inlet pressure would be much lower as the torque under load will pump oil out faster than the trans pump can supply it and pull inlet pressure down below outlet pressure. Hard to believe but I found it once.
Now if the pump pressure with warm oil doesn't hold 90% of value at high idle when you throttle down to low idle check pump.
If pressure is good at low idle feel the cooler lines up to cooler, should be a block that both go through along the LH side of frame near front engine mount. Look for one cool line beyond that block. It contains a cooler bypass like a temp regulater in cooling system. Lets oil bypass cooler untill oil is warm. They sometimes stay open and need replacing.
Later Bob

I am having same issue with my 955l run for about an 1 1/2 then converter temp starts getting hot hey Bob how easy is to chenge that regulator out on the cooling lines that you where talking about any help would be greatly appreciated kind of new at this

You should be able to get a big socket onto it from the bottom. Get it warm and feel the cooler lines all the way to the cooler before you replace the valve.
Later Bob

hey bob when i get it warmed up what should i be looking for as far cooler lines go how do i know if the regulator needs changed