R150f Reverse Gear Shift Issue

I picked up a manual transmission for my 1995 4runner with a 3vz. I just rebuilt the engine and I decided to go ahead and put in a manual like I wanted. Anyways, I picked one up from a junk yard and it was fairly dirty so I took I apart down to the gears and cleaned it all up. When I reinstalled the shift forks and rails I saw that reverse was able to engage without the shift bracket being pressed, resulting in being locked out of all gears. The video does a better jon showing it, but it seems the shift detent is the only thing securing the reverse gear in the neutral position. I know it's insanely unlikely you could lurch forward hard enough to slide the reverse gear into position without actually shifting, but something doesn't seem right to me. Like the username suggests, I have pretty much no experience with Toyotas as this is my first one. Any help would be very much appreciated; I am running myself up a wall thinking about it!https://youtu.be/UYS_wXlKztw

 

I am a newer mechanic so I would have no idea. What I’ve noticed on this 2nd gen forum is that most people don’t know or don’t care to answer. I could be wrong but I don’t get very many replies. Sadly I would try your luck with a Facebook group or something else.

 

Thanks evanspen. I am kind of at my wit's end so I'm just going to drop it off at a shop. I just don't have the time or resources to keep fighting with it.