Is my trans going?
 

I suspect that it is but would like some input before I make a mistake. What's happening is some times when I put it in 1st gear and start to let off the clutch it grabs right away but then grinds and stops as I let off the peddle more it catches like normal. This mostly only happens after reversing. I can feel the grinding in both the stick and peddle. It also started grinding in second now and is more prevalent after the trans is warm. Any input is welcome.

Miles, Year, Clutch model, last changed...

First, if it were me, I would change fluids asap, then worry that the clutch is about to fail. If miles are high, could be trans, but there is not a lot of data here. I think transmissions fail slow, with the synchronizers going. They are a pain, but gradually get worse. the clutch or release bearing is kind of a step function. Work, Tow Home. At least that was my experience.

how old is your CAT? And how hot is your shift boot when the issue is bad. A hot cat will bake a trans. I know.

About half your questions are answered in my signature. TDX stage 4 clutch all parts associated replaced at the same time which was about 25k miles ago along with trans fluid (used RP yes I know RP eats the synchro did that before I knew this) no cat for a long time now. Just tripped 146k on the trans. Have done some hard burn outs (yes I know not good to do with the trans in the 8). And it dose seem to be a progressing thing it started before i changed the clutch that's why I changed the clutch. I'm just looking for confirmation to what I already suspect.

check your engine mounts make sure the shifter is going in gear all the way. if you had syncro issues you will not be able to get in gear.

In that case, I have a used trans. It crunches a tad going into 4th at anything over 65, but might do for parts. 146 on the trans is pretty good. I got 130K. However, my cat baked the trans and my daughter hit 3rd instead of 5th at the end of a straight.

parts are available if you are rebuilding. But, you could try new fluids. They are cheap, but really a bandaid.

gear popping out usually means something is wrong in the Transmission. Fluid not gonna help

but seeing that you have some sort of Stage 4 clutch, I would swap that out and put stock/stock-like OEM clutch back in.

As for rebuilding the Tranny, UNLESS you are doing the work yourself, it's usually not worth it, it's an extremely hideous process, parts are cheap, but tools to do the job properly and labors gonna rape u.