I have a 1995 F350 CCLB Dually 460 E4OD 2WD with 75K miles.

Transmission had no issues then on my way to work a couple months ago the trans started hunting for gears and shifting in and out of neutral. When it starting happening I was easy on the truck (35mph zone), pulled onto a side road and the engine died. Check fluid and was ok. Found truck would move without engine dying when in manual second. When engine died felt like someone had their foot on the brake and let out the clutch on a manual. Dropped the trans pan and found the filter had dropped and appeared the filter inlet wsa contacting the bottom of the pan and not getting fluid causing the converter to be locked when the trans went into gear and thus stalling the engine.

I installed Trans Pan with drain plug: F81Z-7A194-BA and filter YC3Z-7A098-BA with Ford rubber trans pan gasket. Drained torque converter filled with new fluid. Truck seemed ok afterwards, couple weeks later I installed the external Dieselsite Transmission Filter.


Issue I have now is the shift to OD is very harsh. Part throttle I'm sure the tires would chirp if it wasn't a dually.

Steps done so far:
Removed the vss sensor and cleaned it off
No Codes active or stored with KOEO, get 111
Speedometer doesn't flucuate
OD light works and doesn't flash, ever.
External transmission filter is plumbed into the return line to the trans, I removed filter and oil was spraying everywhere. Didn't measure rate but there is flow.


I was going to try a different brand of fluid and new internal filter but don't expect that to work. Any suggestions?

 

Sounds like the 4th accumulator regulator valve in the accumulator portion of the valve body could be sticking. When these little valves stick the shift can be harsh.

 

Next step would be to remove the accumulator valve body and check if the piston is sticking.

Would the Sonnax kit 36948-12 bore sizing tool and 36948-09k 3-4 accumulator valve control kit be the correct fix for a sticking 3-4 accumulator valve?

 

Assuming you have no codes that would jack up line pressure, you have broken springs in the OD accumulator lineup.

 

Correct, no codes present.

 

I removed the accumulator valve body. No broken springs and the 1-2, 2-3, 3-4 valves move with a screwdriver slid into an open slot and slight pressure applied.

I'm not seeing any obvious reason for the harsh shifts. But I'm not a tyranny expert.

Any other ideas?

I bought new accumulator valves, springs, and line pressure modulator. Stock line pressure modulator is .371 inch. Should I replace with stock size or go one step bigger (I have .371 inch and the .427 inch on hand new from sonnax).

 

If you go larger, it will shift firmer.