tie rod came apart on 2005 prius

I've seen it happen before, but not on a Prius. When was the last time that the car had a front end alignment?

It happens, when the mechanic doing the front end alignment fails to correctly tighten the nuts and bolts that hold the alignment length adjustment sleeves. Over a long period of months, the looseness causes the pieces to work back and forth against each other to the point that the tie rod end slips out.

In the case that I have observed, the thread in the tie rod end were worn smooth. The adjustment sleeve was reusable.

 

how many miles on her?

 

It's not too bad on the freeway as long as you don't panic. And IME it's pretty much impossible unless a cotter pin was missing and the nut wasn't torqued properly, both of which happened to me thanks to a poor memory and not enough inspecting before I took one of my cars out.

 

I’ve taken my 2006 Prius in every 6 months like clockwork. I lived in Hawai’i until Fall 2010 so didn’t put much mileage on her, then to Nevada for a year, then to Georgia. At 70,000 mile checkup last month I had them rotate, and align the tires. I had also noticed some “play” in the steering...but it had been recalled to put in new steering column splines (10 years after recall!).
They put in new rack and pinion and new tie rods---$1100 with 5 hours of labor. Does that sound right?

I don’t know if that’s fair...but I live near the Alabama line and no one likes these FOR’N cars! I couldn’t even get a jump start from AAA when I first moved here. I finally told the guy to pull his truck up and I’d jump it with my own cables. I showed him that you can jump it in two places...under front hood (fuse box) and in back where the 12 volt is stored.

He thought that he needed to jump the lithium ion battery. Rural Georgia--Yee-haw! I have to drive 120 mile round trip to get to a Toyota dealership. It’s like owning an old Jaguar trying to find someone to fix this. In Honolulu, the number one selling cars are Toyota and Honda. The kids all buy Hondas Civics, build them up and race them.

 

By your description, it sounds like the inner rod that attaches to the steering rack unscrewed from the actual tire-rod-end. That is not a sudden or event and requires the jam nut to be loose beforehand. This would fall under items checked at any PM service under the "basic safety check" category. It's not even possible for the tie rod to unthread itself without DRAMATICALLY changing the way the vehicle handles. It *can* happen, but the vehicle quickly starts to drive badly and veer all over the road as one front tire is pointed into the weeds, relative to the car.

Now, the joint can dis-assemble itself without much warning, but astute operators would often notice a slight play combined with a very light "clunk" when changing directions L<>R. The castle head nut can also unscrew itself from the tapered spindle of the tie rod end and that will usually result in a LOT of clunking and banging over even the most minor road imperfections.

Not a one of these events would normally occur from one service interval to another. More typically, within a few hundred miles of when they were touched last, on the outside maybe a thousand miles.