Shift lever stuck

That is one worn transmission. It looks like you are also missing bearings. With some of the pictures you have put up you might just want to find a replacement transmission. It might be cheaper than buying all the pieces to rebuild this one. It looks like that unit had water get in it and was not serviced at all.

I would start pricing all the damaged and worn parts and see which would be the better option.

So far the money spent is not as much as a replacement transmission from the junkyard. I just received a kit with new synchros. Attached are more pictures of the third gear (I think it is third). I found a chip in it, should I buy a new one?

The rest of the shaft is taken apart, I am ready to rebuild this thing with new bearings, synchros, spacers, clips, gaskets, etc.

I also need to buy some assembly lube.

Chips are not a good thing on a gear like that. They will chew up the gear they mesh with over time. I would replace it.

Any recommendations on chemicals for cleaning the parts and case? I have been using brake cleaner. Anything better or something I do not know about?

I like carburetor cleaner in the can, cheap and gets the job done.

Yes brake and carburetor cleaner whichever is cheaper on a given day. Paint thinner, diesel fuel or parts washer solvent all work as well but they do not evaporate away easily and can be messy.

Attached are some more pictures. While I wait for some things to arrive in the mail, I took apart the shifting rail to clean. The shift finger was a little stubborn to shift because of 1) rust spots on the rail (pictures) or 2) the lugs are stretched, or both. Judging by the pictures of the lugs and shifting finger, what do you think?

Also, pictures is a set of wire-brush wheels for a drill I got for free from Harbor Freight. It says good for "any" surface cleaning job, but would it be ideal for cleaning the rails and/or the mating surfaces on this transmission?

Lastly, I have also pictures the offset shift lever. Some people say that the points wear. I do not think this one is bad but it would not be a surprise if it happened to be.

Those are simple steel brushes but soft they do not remove rust so much as burnish it pretty. For the mating surfaces use a scraper to just get the old sealant/gasket off. Wire brushes will work but it is easy to gouge the aluminum. Harbor Freight also sells evaporust and fine wet or dry paper. Get some of the 500 and 1000 grit, soak it in water and use that to just polish the surface, you do not want to keep going until the pitting is gone but you want to remove the sharp edges of the pits.

Alright guys,

Yesterday my new third gear came in (finally!) And I got the transmission rebuilt and today I put it in the truck.

And. It shifts beautifully!

I want to thank you guys so much for the help, tips, and support!
Though it did take some time, and most of the time I sat here waiting for packages, I did learn a valuable skill and discipline regarding auto repair.

Again, thanks!

Everything shifts normal under normal driving, but the driver says that the engine just "revs" in fifth when he shifted to fifth while taking a turn.

Sounds like they did not press down on the clutch enough, or?

Update:

Everything does shift well, but the engine simply revs when in fifth as if it were neutral. There is no grinding, no noise, nothing crazy. Guessing the clutch is going? The clutch is not stock, it is one year old now (no clue on mileage).

Have him shift it through each gear and floor it. If it is the clutch it will slip worse through each gear. Also, try starting from a stop in each gear. If it is slipping it will show up.

Well it's been nearly a year since I've rebuilt this unit and we've been ignoring the fifth gear and doing just fine. Ironically at this year-mark, there is a grinding noise when shifting. Surely these new synchronizer rings aren't acting up already. Maybe it just needs an oil change? It hasn't even been driven 20,000 since the rebuild. I'm going to try to get a video soon.

That could be a pilot bearing issue or clutch drag that isn't removing all of the torque from the input shaft. The fifth gear issue almost sounds like the gears are not meshing or it is spinning free. If you want to see a lot of repairs on one and maybe get a better answer take a look at the GearBoxVideo channel on YouTube. Paul builds some mean gearboxes.

I used his videos to rebuild this transmission a year ago. That's why I'm leaning towards the clutch being the issue. I replaced just about everything in the transmission.

Could very well be clutch or pilot bearing. Both can drag and keep the input shaft spinning.