Melted Plastic in the Transmission?!

I posted earlier this month about my 1996 Ford F150 4x4 manual tranny truck. It had gotten stuck in fourth gear, and I, along with others, assumed it was the shift forks. I cracked open the top of the transmission yesterday, and what do I see? Melted plastic staring back at me. What’s going on here? There was melted plastic jammed between fourth gear and the inner wall.

Is this a case of the surgeon leaving his instruments inside the patient? Could a mechanic have dropped his tuna sandwich wrapper in the transmission at some time?

Look closely at the shift lever housing. I believe that the shift lever operates in a spring loaded plastic sphere shaped busing which often breaks and causes all your problems.

One of the parts from this?

It’s an M5R2 transmission.

The shift forks each have nylon ‘‘shoes’’ on their tips and there’s a plastic oil trough on one side too…any of those m.i.a. ?

Ken, that trough looks really suspect. The glob of melted plastic had a longer bit sticking out of it. So it very well could be that. Where does the trough go?

I think I know where it is. On the left side, near the bottom, connected by a bolt from the outside?

Yeppers…but…Ford does not sell that part number anymore.
A few dealers still have NOS ( new old stock ) E8TZ-7A174-D

Ok, ordered the part. Only $17.