Update: I got the switch fixed.
Here's what I did, so hopefully this will help the next poor soul that experiences this. :)
First off, my diagnosis was incorrect. The actual key tumbler cartridge was perfectly fine. The problem was with the cast aluminum rod that the key rotates to activate the various switches that operate the car. That rod is about 6 inches long and has several cams on it, a brass spring loaded blade that plugs into the key tumbler cartridge and a keyed end that plugs into a round shaped switch that has the spring inside it. In my case, the rod had an interal defect that caused it to have a weak spot and it snapped in half. Note to Lexus/Toyota: This is a poor design! This problem is due to poor engineering design. There is no excuse for using a cheap cast part rather than a machined part. I spent much time and effort attempting to order a new rod from Lexus and Toyota and finally determined that it is impossible to order this indivual part. They want to sell you the entire ignition switch assembly for over $800 and if you plan to do that, I recommend you spend another $600 to have it installed. You need special tools to remove the ignition switch assembly from the steering column and this is not a job for the feint of heart.
The way I ended up repairing the car was to use some JB Weld to put the rod back together, and then I took it to a shop to have it welded. In my case, the crack was very close to one of the cams, so it was impossible to weld it without having some of the welding metal get on the cam. So, I needed to use the dremel tool to grind off some extra material once it was welded.
If you are reasonably mechanically inclined, this is not such a difficult repair, but you will need plenty of patience and bandages. It's a tight area that you're working in and your hands will get pretty sliced up.
Tools required:
Phillips Head screwdriver. A ratchetted one is a big plus
Set of metric box wrenches. 6mm - 14mm is what I had. I recommend ones that have a ratchetted closed end on one side.
Metric socket set.
Impact wrench and metric impact wrench sockets. I used a battery powered Makita with 76lb-ft of torque.
Needle nose pliers.
Dremel rotary tool with cutting wheel and gringing tips.
Assistant (spouse, buddy, kid, etc)
Disassembly:
This is the hard part. Remove the covers below the steering column. There is a plastic decorative cover and a metal cover that need to come off. Follow the steering column down to the floor and slide the rubber boot back as far as you can. It will expose 4 bolts. You only need to remove 2 of them. There are 2 bolts that directly connect to the steering drive line and 2 that would only be used if the main bolts fail. You will need to rotate the steering wheel around to access the bolts. Slide a box wrench in and loosen each of the 2 bolts. You may need to get your fingers in to the underside to keep the nut from spinning. Once those are out, disconnect all of the wiring loom connectors from the steering column. Next, firmly pull down on the ac vent duct that runs across the steering column. A section of it will come out pretty easily. Look up inside and you will see the 4 nuts that mount the steering column to the dash. Use the impact wrench to remove those. Your trusty assistant comes in to help you here. I suppose you can do this with a socket set, but an impact wrench is really the proper tool for this. Remove the steering wheel from the car.
Repair:
There is a small black ring that surrounds the key tumbler cartridge. It is held on with a single screw. Remove this. at the back of the ignition switch, there is a white plastic cover that is held on with two screws. Remove this. Put the key in the ignition switch and rotate it to "ACC" mode. There is a small hole on the side of the ignition switch, about 1/2 way down. Inside that hole is a button that you need to press to remove the key tumbler cartridge. I used a jewlers screwdriver for this. Remove the key tumbler cartridge. Using the needlenose pliers, remove the rod. I had to wiggle and shake the ignition switch around to get both pieces out because the switches inside were holding one piece in place. A combination or needlenose pliers, screwdriver and patience managed to get the small piece to come out. Assess the damage to the part and then use JB Weld to glue it back together. In case you're thinking that JB Weld is strong enough to be a permanent fix, I remind you what a pain this repair has been thus far, and encourage you to get the rod welded!
I have a buddy that works at a machine shop, so this repair didn't cost me anything, but I expect the labor involved to weld the part would be around $50 at a shop with similar capabilities. Look through the yellow pages in your area and you should find a ton of machine shops or other places with welders working there. Muffler shops and auto body shops would be other places to try if you are not having much luck. An experienced welder should be able to quickly determine the best way to fix it for you. Ask him/her to try to do as clean a job as possible around the cams so you don't need to do so much cleanup work. If the cams themselves are damaged, have the welder put some extra material on them so you can shape new ones with the Dremel tool. It took me about 30 minutes of Dremelling to get my part back in shape. Just be patient and take off a little material at a time.
Reassembly:
This is basically the reverse of dissasembly, but here are a few gotchas to watch out for. How do I know about these? :whistles:
1. Bolt the steering column back to the steering driveline assembly on the floor first. Only hand tighten the nuts and I suggest installing them the reverse of the way they were done at the factory. I put the bolts in from the bottom and put the lockwasher and nut on the top.
2. Check that you installed the steering column with the steering wheel the right way around! It will fit in both ways and you will feel really crappy when you drive the car and realize that the steering wheel is upside down. Adjust as necessary. Once you are sure that the steering wheel is right-side-up, tighten the 2 bolts that attach the steering column to the steering drive line.
3. When you put the ac duct back in, put the right side (side that attaches to the center console) in first.
4. Reconnect all of the wiring loom connectors or the car won't start. That black ring that you took off to get the key tumbler cartridge out has a sensor that detects that you are using the proper key. If you don't have that plugged in, the car will turn over, but won't start.
5. The extra black screw that you can't figure out where it goes attaches the ac duct to the plastic dash.
Good luck!
