M5OD transmission pops out of gear

[Medic-Holt]

Hey I'm new to posting but I cant figure this out. I rebuilt the transmission and now whenever I go to put it into 5th(OD), as I let out the clutch the shifter pops into neutral. Took it into a shop, they told me my syncro was in backwards. They took care of it and I put the trans back in the truck. Now 5th is fine but its doing the same thing in reverse instead!!! Any ideas whats causing this? please help, I dont have much hair left to pull out.

 

[little x]

If reverse used to work fine until you took it into the shop then the shop messed something up. Take it back and tell them and they should fix it for free.

 

[Medic-Holt]

no it was doing this before I took it to the shop. I rebuilt the trans and it was doing it after I rebuilt it. All the shop dd was flip the sleeve for 5th and Reverse because I put it in backwards.

 

[Medic-Holt]

Right now I'm more looking for what would cause this to happen. Any ideas?