the antenna on my recently purchased 2006 SC430 does not retract 100%. It remains about 4-6" above flush. Is this normal?

 

No, that is not normal but it does happen. Typically it is one of two things: either the shaft is slightly bent or it needs to be lubricated. To lubricate, have someone run it up and down while you wipe it down with a rag sprayed with silicone in between runs.

 

Does it go up? Can you push the antenna down with your hand?

If you can push it down, then my guess is the plastic piece inside is broken. The motor is sucking down the lower part below the break, but not the upper part.

It is an inexpensive fix, but depending on where the break is, it could be a complicated fix

If you can't push it down, you are in better shape. You can replace the mast much easier. Here is a video for that:

 

I tried spraying the mast with silicone. That did not work. The antenna goes up and down. It just does not go all the way down. As i said previously, the last 4 inches stays out.

 

You PROBABLY need this video then.
But I would still hold out hope and try to just replace the mast. It's easy if u follow these instructions
https://www.clublexus.com/forums/sc4...l#post10777358

 

I recently purchased my 06 and the antenna was bent by the dealership. Someone forgot to let it down before going through the wash. If you can hear your motor working, which I assume it is being the antenna works to some degree, just save yourself the headache and let Lexus replace the mast. It wasn't expensive a little under 200.00 part and labor. It's worth it for me of course I like knowing my baby is being taken care of especially electrical stuff. If your motor wasn't working then you'd be spending even more money. Be careful with letting it up and down as a broken tooth on the mast can cause you to have to go in the motor or replace it. My opinion let them replace it. They did a great job and it was shiny and new lol.