Removing Stuck Outer Tie Rod End (TRE)

My 2009 Prius outer tie rod end kicked my butt this week. What was supposed to be a quick 1 hour replacement took 6 hours over several days.

The vehicle's mileage is 244k, all of it in Indiana. The outer TRE wasn't particularly rusty, leading me to believe the beast could be replaced with minimal effort. Wrong.

Advice to others who try this:

1. The aluminum control arm has a hardened steel bushing press-fit into it to accept the outer TRE. The inner bore of the steel bushing is tapered. The taper matches exactly the taper of the TRE. The significance of this is that torque on the castle nut forces two tapered steel parts together VERY tightly.

The taper is extremely shallow so even modest amounts of bolt torque merge the TRE and bushing into a single metallurgical entity. Add a little water, road salt, and time and this merging of steel parts is quite literal.

2. Do NOT use a 12 point box end wrench on the castle nut, not even once. Only use a deep well 6-point socket and tap it onto the castle nut to assure tight fit. Then--but only then--put the breaker bar on the socket.

Toyota's outer TREs are constructed from hardened unobtainium Toyota mined in another galaxy. (That's why the outer TRE lasted 244k miles.) However, the castle nut is simply soft, earth-bound steel. Your breaker bar cannot break off the threaded stud on the TRE, but it will absolutely round off the shoulders on the castle nut.

3. I next sawed off the castle nut with a hack saw, exposing the raw threaded stud in the TRE. I put a fresh nut on the stud and pounded on it with a hammer with zero movement of the stud. I heated the stud and bushing with a propane torch but the sucker would not budge. I tapped on the control arm with the hammer, also without effect.

3. Next I used a gear puller whose claws were anchored on the aluminum control arm. The center threaded pin of the gear puller was parked atop the new nut I placed on the TRE's bolt threads. The nut serves as a centering assist while you torque down the gear puller.

4. In my case the gear puller did not separate the TRE from its bushing, but it did separate the [bushing +TRE] from the control arm. This is a mild blessing even if the result was not what you predicted.

Once I had the [TRE+bushing] mounted in a bench vise I pounded on the bolt more with a hammer. No luck. It eventually required an oxyacetyline torch to heat the bushing to cherry red to get it to separate from the TRE's bolt.

Have fun, boys. No way I'm gonna tackle the TRE on the other side of the vehicle. If it ain't loose, don't fix it.