This is my first post although I have lurked for years and benefited greatly from the knowledge on here. So first off, Thank you for the forum.
I tried to search on the forum but I did not come up with any resolutions.

Background: 1995 Ford F-150, 5.8L, 4x4, 145,000 miles. Blew out front seal while towing a hay trailer through a hilly pasture while loading hay on trailer.
I debated just replacing the front seal and calling it done as I previously had zero issues with the transmission. I decided to rebuild instead. Mistake #1.

I purchased quality parts, and referenced multiple sources throughout the rebuild. I have the factory service manuals, and purchased the ATSG transmission rebuild manual. I also found several electronic rebuild manuals and step by step how-to's. I thought everything went well. I upgraded most pieces. Installed new bushings and bearings. Installed the code 62 pump correction kit even though I never had any issues. ETC, ETC.

What I didn't do was adjust the clutch pack clearances. I checked one or two and the clearance was larger than specified. I tried to adjust the clearance with what I had on hand (extra clutches and steels etc) and it was too tight. So I went back to the correct number of steels and clutches and assembled it assuming "It was ok before with worn clutches, surely with new steel and clutches it'll be ok" I didn't want to wait and order the corrective thickness snap rings. Mistake #2.

When everything was reassembled I had a single steel ball left in my parts tray. It was larger than the check ***** and steel. I searched all the manuals. went over all the procedures. I watched several you-tube videos. I never found a reference to this steel ball or where it might have come from. I finally gave up and assumed it came from another project. Mistake #3 maybe?

I put the transmission back into the truck confident everything was going to work perfect. I had to replace the connector on the wiring harness because I broke the connector on removal. Mistake #4.

I test drove the truck and was grinning from ear to ear as it shifted through 1,2, and 3. When it shifted into 4 it slammed into gear. I don't know whether to call it a delayed shift or hard shift but it gives you whiplash.

I did some research and decided to change the solenoid pack. No change. 500 miles later it stills shifts great till 4th. Accelerating from a stop, it shifts very hard from 3 to 4. Pushing the OD button on the shifter, down shift is good, upshift back to 4th or OD is very violent. Modulating the accelerator to down shift and then upshift gets the same results.

So, Do I open it back up and adjust the clutch pack clearances? Does that steel Ball go somewhere I missed? Is there someplace else I screwed up?

Thank you for any and all help or suggestions.

 

My first thought is a stuck 4th Accumulator Regulator Valve in the accumulator valve body.

Loose or tight clutch packs shouldn't cause harsh shifts, maybe slips/flares or bind ups.

The large steel check ball doesn't go with this unit, there is a smaller one that sits on the spring under the plate.

 

Thank you for the response.
The small steel ball is in place on top of the spring . I assumed after much research that the large steel ball I found was from another project. Thank you for confirming my assumption.
What is the best way to test/repair the 4th accumulator valve?Just make sure its free to move and that there are no ridges to hang up on? Is it best to just replace the whole body?
Thanks