E30 getrag 260 popping out of 3rd gear only

[Obito22]

https://youtube.com/shorts/SLRWukk4ESE?si=Jw_X7unrStBweDw7

So here is a link to the video of what is happening but basically all my gears work and feel fine except for 3rd gear , wether I shift from second to third or down from fourth to third it always pops out of gear and vibrates as seen in the video. Occasionally it will work perfectly for about 3 or 4 shifts then it will go back to doing the same thing. The only way it works is if I hold it down in third with my hand as I release the clutch as seen in the video as well. All my other gears work just fine and I installed a new pilot and throw out bearing not that long ago. I noticed it started to do this when i installed the turner motor sport reinforced shifter linkage that connects the shifter to the transmission, I replaced my selector joint but I still have the same problem. Does anyone have any clue as to what it might be

[82eye]

make sure you have free movement in and out of third when it's not running. if you have no issues your linkage should be ok. if it still pops out it'll most likely be your clutch plate and forks giving out.

the fix is a new clutch and pressure plate. if that doesn't fly it's likely internal and will be expensive enough to fix that another tranny will be the best answer.

[Northern]

I'd get under the car with it in third and check that Turner linkage and make sure it's not binding, hitting the guibo/harmonic balancer, etc.

Some shifter+DSSR combos like hitting the harmonic balancer. IMO I'd remove that and throw it in the trash without a second thought if it is the issue.

If you see nothing, then I guess swap back to the old stuff before you go after the trans.