Your description sounds like a broken sun shell (reaction drive shell) inside the transmission. You normally will hear it whine and lose reverse and second gear, so it will start moving then shift hard into third gear, it won't even try to engage second which is why it shifts really hard. It is also one of the most common failures in that transmission. You won't see anything in the fluid until you try to run it a lot with it broken. It doesn't break from wear; it breaks because it's a bad part and the splined hub shears off the shell. The curb hit was probably just enough of a load for the hub to fail. I've had them fail just driving down the road or going up a hill.
The only repair is to either rebuild or replace the transmission. Personally, I suggest rebuilding it and using one of the heavy-duty kits with a hardened shell. That removes the weak part and gives you a much better transmission. If you don't have the tools to rebuild it look for a shop local to you that has a good reputation and price it through them. The other option would be a used transmission. Unless you can get it really cheap and replace it yourself, I'd suggest avoiding that, mainly because you could have the same problem with the replacement unless it has already been rebuilt.
This is pretty much the same replacement process you would use, except with the 4X4 you will have a transfer case bolted to the rear of the transmission in place of the tail shaft housing.
https://www.2carpros.com/articles/how-to-remove-an-automatic-transmission-rwd
Feb 24, 2022 at 8:46 AM
