Got the trans disassembled just to see where the crack was internally and what condition all the internals were in. The crack along the top is right at the pump shelf sealing surface and as it gets towards the bottom, migrates into the machined surface along the side of the pump. Internally everything looked better than I was expecting. Only damaged hard parts were the direct drum wear from the toasted band and some wear on the input shaft at the pump bushing. Direct band, direct clutches and intermediate clutches are all toast. I was expecting to find the intermediate sprag rolled but it was fine. Two of the forward steels had a very minor hot spot on them but the clutches looked fine. OD assembly looked new but I dont put trans in OD all that often. I presume based on where the crack is at the pump outlet, there was a gross leak and pressure loss causing the burnt clutches/band. Input shaft wear was likely from the slight misalignment behind the pump due to case sagging at the crack.
Now for the carnage pics...
Case crack into the dipstick boss...


Cracked case...


Case crack along pump shelf sealing surface...


Case crack around pump shelf into park pawl void...


Case crack along machined pump surface...


Clutch material in accumulator...


wear on inputshaft from pump bushing due to misalignment...


Sliver of material from direct drum. Looks like casting flash broken off...


Close up of sliver...


Band wear on direct drum...


Burnt direct clutches...


Band completely worn down...


Burnt intermediate clutches...


All laid out and labeled on bench...


So now I am looking for a rebuildable core or a good case to transfer everything to with a new direct drum, clutches band and intermediate clutches.

 

A little update to close this saga out... Found a 2005 4wd core at a local salvage yard a few weeks ago that I picked up for cheap. It looked like it had been in a mud truck but the case was in good shape so I took a leap hoping the direct drum and valve body were good too. Upon disassembly it was obvious it had some water ingestion and someone had been in it previously but the direct drum and valve body were good. I wanted to do a full refresh with bushings and frictions but my trans parts guy never called me back over the holidays so I decided to just use all the parts I had on hand. Luckily I had already all the necessary new gaskets and seals I needed. I took all the best parts from each trans and a set of stock frictions/steels from my original trans I held on to after going thru it in 2009. Previous build had an early HD2 kit for dual feeding the direct clutch so I used some of those pieces (VB springs, Boost Valve, HD Intermediate Snap Ring) in the new build where I did internal mods for dual feed. Got the converter back from FTI from a cut&clean, new bearings and clutch Friday so I got the trans buttoned up and back in the truck over the weekend. My mismatch leftover parts bin trans seems to be working great. I couldn't give it all the beans due to the wimpy NT05 tires but trans seems to be transmitting power well in all gears.

I still have a small vibration on acceleration at speed but I think it may be drive line angles. I measured the rear and adjusted the wishbone as much as I could but there is still a 3 degree difference from it and the trans. Working angle at the trans is 5 degrees and it is already spaced up 1/2". Moving it up any more pushes the exhaust up against the cab floor. I have been wanting to redo the exhaust anyway so now this is just more motivation to do so.