460 gas, with plow & slide in Brimar dump, less than 60k miles.

On short trip when noticed trans slipping a bit. Engine runs hot when drive at 55 with plow mounted so was watching gage. Engine stalled so coasted off road. Engine blew bit of steam and front of engine covered in ATF. Checked trans dip stick and no ATF. Returned with coolant and ATF. Topped of coolant and ATF. Now trans makes absolutely no effort to move truck. Does not even rock drive shaft back and forth to take up normal looseness it rear axel. Rechecked trans fluid level, watched shifter lever on side of trans move when helper shifted and shifted trans case thru all gears.

Two things puzzle me.
1 Was slipping a bit but pulling before engine stalled.

2 Trans cooler lines no longer leaking. I let it run for 30+ minutes. Could trans not be picking up oil from pan for some reason or pressure regulating valve in trans suck open?

Sad back story in case it gives any ideas. No problem with trans for the years I have owned truck. Weather had been in minus 20’s (yes Fahrenheit) for few days before but was currently in 50‘s and raining, ditches were full of water. Was plowing slush off my driveway before it got cold again. Tire sunk in mud on edge of driveway, till rear pumpkin on solid frozen crushed stone of drive proper. Jacked up truck & packed stones under tire. Drove to quarry to get crushed stone to finish filling rut. No problems with trans, but power steering not all there. Noticed some pink snow will positioning truck to drop stone in rut. Wrote it off to leak in steel cooling loop in power steering return line. I had noticed cooling loop rusting and had meant to replace. Went to move truck one more time and battery dead. No big surprise, 8 year old battery and had been working electric dump without engine running. Go to pop out battery and front of engine covered in ATF. Still thinking from power steering. Figure alternator slipping from ATF. Temps dropping, snow coming and want to finish filling rut. Charge battery for 20 minutes and heading back to quarry for more stone when noticed trans slipping. Thinking about heading home when engine stalled. See above, but add recharging battery.

Appreciate any ideas.

 

Does the trans have enough fluid? If it isn't low, it's probably trashed. A slipping trans will usually last less than a mile before it's destroyed.