Are you telling us that the prop shaft will not turn when engine is not running?

Yes, 100%!  Solid as stone right now.  Thus the reason I was beating on the prop shaft trying to get it to free up.  I could crank on the engine a bit more which would throw even more torque at it, but I don't even know what is actually stuck or why.  

I ran a test with a pressure gauge directly on the trans pump as I monitored the dash gauge which is after the pressure side filter pack and valving in the trans. There is a significant difference, indicating plugged filters. However, thee trans pump pressure is far from stable. When I brought rpms up a bit, I saw the pressure climb above 400psi so I kept rpms low to hover around 300psi. As I dropped into a gear, the pressure at the pump would drop to about 150, then come back up. It was consistent with every gear selection. The dash gauge would drop to pretty much 0, then climb a bit. I suspect the filters are trying to bypass, which is not what I wanted!

I figured out that I could select gears 1, 2, in RV and FW, but could not get 3. Not sure if pressure is an issue there or not. I will have to try filters and see what that does.

In any case, not one thing I did changed the sound or indications it was actually in a gear, and the prop shaft never moved.

I do have concerns on why the pump pressure regulation is not good at all. I expected it to climb and hold but it was all over the place.

Before you totally destroy the transmission, it is time to remove, dismantle and repair it properly, forcing it will only cause more damage, the pressure issues are due to failure within.

Wombat

totally agree with Wombat, time to pull the plug and dissect before more carnage results ! !

-now the puzzle is coming together or unravelling unfortunately

Thought the trans will probably be coming apart, I tend to doubt the "frozen bearing" theory at the moment for several reasons. I think 2 or more clutches are engaged and won't release. I might work to get the top of the trans just to confirm that. I just feel like I need to think about any testing I need to do before I open things up.

I can see down the oil fill hole and see the speed selector spool. Nothing is rusted in there at least. Moves easily and not drama on that front.

The main thought on the frozen bearing deal is how recent machine moved, what could actually be frozen, and how froze would it need to be to hold back the torque of a 339? I'd say a LOT. I am hoping to at least confirm the TC or trans tomorrow by uncoupling them. Not looking forward to it, but I guess it needs done.

don't mean to be DebbieDowner but this has gone South quickly..

- i have a neighbour that knows everything mechanical and his D8 was having transmission/converter problems and he did not repair said trans/converter problems correctly..shortcuts in a hurry etc....ended up pooching the engine crank as well...........tread carefully

My guess is the problem lies in the front planetary carrier, it has the two direction clutches, a split ring gear or damaged carrier and planetaries. To lock the transmission to drive, you need a speed and direction clutch engaged. If the prop shaft is locked when motor is not running, you have no oil pressure to engage clutches. Thats why I am favouring a mechanical failure in front of box., you can still tow the tractor so the output end is free.

Wombat

Update. I fired machine while looking down the oil fill hole where fw/rev spool is is brightly visible. No oil was puking but as soon as I dropped into a gear, I could see oil puking. Actual location could not be determined but it covered the valve body that I could see quickly. No spraying, but this is while my trans pressure gauge going into the valve body was super low. No doubt would spray nicely if I speed up the engine or had better pressure.

I also split the yoke and TC didn't have a hint of binding at all. Free as a bird, but trans side is locked. I'd consider the valve unit as the culprit if trans was free but that would not explain the lock when not running.

Thoughts on pulling the top for inspection, or just grab the whole trans? This is not going to be a fun adventure.

Hi bobby1,
you have located the lock up culprit as being in the transmission so as I see it you have no choice but to remove the Trans. and dismantle it for further investigation--the Trans input shaft should turn with some steady resistance only.

Did not get back here soon enough to warn you not to run the diesel engine without the drive coupling installed as oil pressure in the T/C can eject its output shaft, along with much oil, and then you will have issues getting it back into place. This shaft his floating to allow for installation variances--its end thrust is taken by the the Trans input shaft support bearing--later update is to replace the flat roller race assembly and fit a ball race as used from an early D7F trans for better longevity.
Regards,
Eddie B.