M50D popping out of fifth

[IAmTodd]

I've recently completed a manual transmission swap with a junk yard(emphasis on the junk part) trans. Gears 1-4 and reverse function as I would expect them to. Fifth is a different story however. When power is applied you can see the shifter moving back and it will eventually pop out of gear. I have tried adjusting the bolt on the drivers side of the trans and it might have helped some as I can sometimes run in fifth now but it will still randomly pop out.

It will be a little while before I pull the transmission again. I'm not looking forward to that at all but it has to be done. I am looking at what the issue may be. Fifth gear definitely feels different when selecting. All other gears have a noticeable click when engaged, fifth just needs to slide in with no click.

Any help would be greatly appreciated.

 

[IAmTodd]

Just an addition, there was no fluid in the box when I got it so I don't know the condition but there was a good amount of build up on the magnet when I pulled it.

 

[Rick]

If the top of the unit was greasy and it looked like it had been leaking for a long time there is a good chance it lost all it's oil through the rubber shift rail plugs. If that's the case, it's trashed.

 

[IAmTodd]

It was rather dirty but the plugs were RTVd in to seal them up. Looks like I will be pulling it to check on it. If not it will be a $100 core for a rebuilt one.