Well first off I want to thank everyone who has been helping me on these forums I have done a lot to my truck mechanically and for the most part its running smoothly. Unfortunately yesterday I had my transmission lock into gear again yesterday. First time this happened I took the top plate off of it where the shift stick goes down into the transmission and learned its locking up in the top half above the forks its like its not wanting to move out of the position its in but I was able to get it free after playing with it for about a half hour. This time same thing except I am not able to get it free. It acts like its shifting into 1st and 2nd but will not find neutral or 3rd and 4th gear. I have tried to run the truck in 1st or second and it just automatically dies when I let off the clutch. So here are the following questions 1st I have looked and looked online trying to find a rebuild kit for the top cover and forks but have not found one nor have I been able to find the plastic pieces that go on the end of the forks any ideas? Second I have called around to every junkyard and auto parts store within a hundred miles no one has the transmission or that top cover what other transmissions can I just plug right back up there without modifying anything? It is a 1986 f250 with the 300 I6 in it. It currently has a 4 speed transmission and it is 4 wheel drive.

 

If you have the truck sitting on any kind of hill, there is going to be enough pressure on the trans to make it difficult for you to move the shifter levers around. If you are on a hill, chock the wheels and then push in on the clutch while you try and release the levers in the trans.

Do you have the t18 transmission? You would not have the closely related t19, but you could have the new process, I think it was a 435.
The Novak Guide to the Borg-Warner T18 & T19 Transmissions

The Novak Guide to the New Process 435 Transmission

Once you figure out what trans you have, then you can look for parts.

The people above sell parts for the t18
https://www.novak-adapt.com/catalog/.../t18-t19-parts

 

OK I went out and measure it that seems to be the easiest way to tell. I have a new process tranny. I looked and couldn't find anything that would show what the difference in the 2 being hooked up to the engine would be. Any ideas? I think I found a t19 tranny have to wait to hear back from the guy but I know he didn't have any new process ones

 

t19's where behind diesels and 460's. Will it fit? Maybe. Check shaft sizes and u-joint sizes on the output.

 

The easy way to tell is that the New Process has an aluminum lid and the Borg Warner has a steel or iron lid.

Novak, Midwest Transmission and American Powertrain Warehouse all list shift forks for the T-18 and NP 435.

I guess I'm not sure what you are looking for?
You cannot even be sure what you need until it is on the bench and open (unless it is something obviously bent or broken)

 

T18's, T19's & NP435's all interchange directly as far as the bellhousing & clutch are concerned.

I've had both a T19, & an NP435 in my truck without having to alter the driveshafts.........even though there is a slight length difference.

 

1986 F250 300 I-6 4WD could have a New Process 435 (NP435) or Warner T-18.

NP435: The shift lever retainer cap (B8T-7220-D) has two notches, is retained to the shift tower with two pins.

This cap must be pressed down by hand and held down while turning it counterclockwise to remove it.

Some people are unaware, use pliers to remove it...which tears out one or both of the notches. Not pleasant!

Warner T-18 shift lever cap (8MTH-7220) threads on/off.