Hi everyone, long time reader of auto threads, first time poster. I know there is a lot of etiquette involved on these threads so I apologize in advance and ask for patience with this newbie.
I have a 91 f350, 460 with e4od, 4x4 crew cab. I love this truck. It was affordable and it fits my whole family. I think the truck has 150k on it, but it's possible it rolled over, but I was assured it was 150k. The transmission was rebuilt at 100k.
​​​​​​Long story short, I was driving in the mountains, ran over a newly asphalted construction trench going about 35 mph on a mild inclined grade. The truck slammed pretty good and I immediately lost all gears. Barely made it to the side of the road and out of traffic.
​​​​​Dropped the pan, fluid was dark red, the pan was dirty and the magnet was full, but there were no large shavings or anything that looked bigger than soot.
I was encouraged when I dropped the pan because the filter basically fell out and I figured that was the entire problem.
- Replaced with new filter and fluid, no change. Repeated this to make sure the filter was seated properly, no change.
- Pulled the top coolant line and the pump was pushing fluid
- Transmission seems to be whining a little
- All linkage is in place and is shifting properly
- I've noticed when I shift the gears, the rpms actually increase slightly when engaged.... Which seems backwards
- pulled the plug harness and added diaelectric grease, no change
- no codes that appear relevant: 21, 41, 77

It makes zero sense to me, but I know transmissions are complicated. I couldn't be more frustrated and am ready to take it in for a rebuild. How can a heavy duty truck loose ALL gears, completely, by hitting a freaking bump in the road?

This is a hail Mary... Any advice? Any insight?

Thanks in advance.

 

Check the grounds and plugs

Edit: I realize my error in this post. I didn't finish reading it and was very busy. After reading the original post this is definently mechanical. As to what is causing the issue, I'm unsure.

 

here is some info on harness
E40D: The Importance Of A Clean Trans Harness. - Ford Truck Enthusiasts Forums

 

Diagnosis by Symptom:

 

Thank you for taking the effort to locate and upload this. If I am reading it correctly it rules out any electrical connections or solenoid issues?

 

Yes that is true.

 

That's a total waste of time. NOTHING electrical can cause this.

That is correct. It has to be something mechanical. Usually, it's something that transmits torque that has broken. That requires a rebuild.

 

I am appreciative to all of you who commented.

Has anyone ever dealt with Best Buy Transmissions out of Florida? They advertise a beefed up remanufactured e4od, with an upgraded torque converter for 1850 delivered. 5 year 100k warranty. Solid reviews, but it seems too good to be true, right?