Jax was hanging on for dear life on a railing of their truck, which was ramming into the other truck beside them that belonged to the bad guys. How did this happen? Well..

Kinger had thrown an ancher to Pomni who was on the roof of the bad guys' truck. The ancher was attached to their truck. And the ancher fell into the gorge.

So, their truck headed towards the gorge and rammed into the other truck while doing so. The force caused Jax to flip and now be hanging on for dear life. "JESUS!"