On our last trip of the year our tow bar failed on the way home. Our CRV was not tracking right. After stopping a couple of times I realized the right arm was not staying engaged. The spring was not working on the release lever. I ordered a new set of springs from etrailer.
They are a pain to replace. Here is what worked best for me.
Pull plastic cap. Remove holding pin with hammer. Hold handle down (tape or helper). Put spring with bent end that goes over the pin first. That gives you just enough space to angle and get the straight part into the top of the tub. Push in with strew driver. The hard part was keeping the spring lines up to get PIN back into place. I used a drill bit to line the spring the tapped pin back in place.