help diagnosing esc trouble

[arbitris]

Wraith RTR poison spyder with about half a battery pack of use (it came out of the box and immediately started getting troubleshooting.)

The problem: When I try to climb a stair I get about 1/4 tire turn and it will lose all power and just flop, then repeat. Once it powered itself off completely and I had to unplug the battery and re-plug it back in. It also has very noticeably less power and speed than my scx-10, even running the same motor/battery in the scx, putting them in my wraith and running it back to back.

I have searched and I found: Check battery charge, I charged and even tried different battery packs. Check solder on batt connection, (cut and re-soldered 3 new connections). Check motor to esc connections. They were literally wobbly loose, so I crimped the female connecter a little so it was tight, and then soldered the connection, still having the same problem. Check the motor, maybe it needs rebuilt: Nope, I have tried 3 different motors, 1 used known good, 1 new in the rtr kit, 1 broken in and installed.

Am I missing anything? Does anybody else have another suggestion for troubleshooting? Or do I need to wait until Monday and call axial support?
Thanks for any suggestions.

[Crank]

Have you noticed any steering troubles?
Maybe try a different servo?

[arbitris]

The steering does seem slow and weak compared to the same (stock) servo in my scx10, although I'm using an xl-5 in it which has a built in 6v bec.
I was inspecting the servos and they both have what I would call an alarming amount of shaft end play.
I'll run a backup servo and try again.

[arbitris]

I snagged another esc from a friend and it's performing as I expected.