A broken antenna mast is a very common problem for Lexus LS400 and SC400.
Both vehicles share the same motor and mounting position. The two most common mast damage include but not limited to wear and test of the plastic gear and physical damage to the mast itself. One of my experiences was having my radio on while going through a gas station car wash. This is a no no.
This article is to show you how to replace the antenna mast, assuming your motor is good.
- You need to remove the locking cover from the antenna housing. You can use a pair of long nose pliers.
2. Once the exterior locking cap is removed, now you need to use a 10 mm shock to remove the antenna housing. You can get access to the antenna housing by removing a cover on your left hand side. You need to unplug both the power/control source along with the antenna signal cable.
3. Once you got the whole housing out, you need to remove the broke mast shaft and the plastic gear.
4. If you can not get the plastic gear out by pulling from the top, then you would need to open up the black gear box. However, most of time you can get the plastic gear piece from the top using a long nose pliers.
5. Once you got the two pieces and sometime the mast and plastic gear is connected. The next step is to install the whole antenna housing back along without the locking cap.
Here is the trick to get this right and you will need a friend to help you with this. Have your helper turn on the ignition key and turn on the radio. This will active the antenna motor to go up. Once the gear goes up and stop, then u insert the plastic gear from the top of the housing (outside of the car) the gear should be facing the rear of the car.
Once you inserted all the way in and the motor will stop you from going any further. Have your friend turn off the radio and the motor will lower the antenna. The motor gear and the plastic gear will match up and start to suck the mast down.
Use your hand to guide the mast until the motor stop. Once it is fully stop, then u can push the mast down a little and you are set. Replace the cap screw and you are done. This is how it would look before inserting the mast.
Here is a video I made to show the process. Enjoy.Do you have any questions? If so, please head over to the forums to get a quick answer or share your experience!