I just recently did new wheel bearings & brake pads on my 2000 civic si. This has a B20V motor, it was driving fine until I started going from a green light, very slight incline, the car moved forward a bit and then there was nothing going to the wheels. I wasn't even beating on it at all.

At first I thought maybe an axle popped out but I checked and they're both in the splines.

I pulled my passenger side axle out from the transmission, when the car idles you can see the splines inside the transmission spinning (even in neutral), but when the axles are in they won't turn no matter what gear it's in.

The car does go into every gear but I always knew 2nd & especially 3rd gear were always finicky.

This is gonna be my first time getting into a transmission so any ideas on what probably went wrong, or any advice that I could follow along the way is much appreciated.

I did take a picture and a couple videos, there is some noise coming from the trans but only when the car is in gear. Maybe someone has an idea of what happened. Again any words of advice are appreciated. Thanks!

Pictures/Videos: https://imgur.com/a/F32Hhd8

 

Also if you check the picture I took of the passenger side axle, it doesn't appear to be in all the way, but honestly it won't go in much further at all.. It is far in enough to where its in the splines & if I spin the axle by hand I can hear the gears turning in the transmission.

 

Shove the axle back into the transmission

 

I'll give it another shot but I had a pry bar on it earlier and it just wouldn't go further than you see in the picture.

 

Take it out and make sure you didn't ruin the splines.

 

Update, it turned out to be the axle. It wasn't easy going in but what really did it was a hammering the axle with a block of wood and that finally made it budge. All is good now. Thanks guys!