Robinsryde

The wifes 01 Rx 300 was making a knocking noise when the heater/ac would be changed from one mode to another. But would still work so I put that job off til the heater no longer blew hot air. I followed the info I found here, and checked a few areas first (thermostat, heater core lines) before I yanked out the glovebox. The pics and instructions were great. After I pulled the servo I took it apart ( no way was I gonna spend $140.00 because of a piece of crap $1.00 motor if I didnt have to). CAUTION go easy on the clips that keep the servo halves together. They crack easy. Duct tape to the rescue, but you can hold the servo in your hand opened up and plug it back in and watch it work when you change the mode. What I saw that was making the noise is a piece of brass that is on the motor shaft that connects the bottom of the worm gear had moved down the shaft just a hair so it didnt come in contact with the worm gear fully fully which is where the noise was coming from. I slid the brass piece up the shaft a hair ( I had to use some force ) and found that it can be moved to far which presses the top of the worm gear into the housing causing it not to move at all, a small correction and put the two halves back together ala mr. duct tape and she be workin. I started to do the same with the hot/cold servo and found no issues when I opened it up. The gears worked fine even when I held them with my fingers the motor could still turn them. I think something with the plug not being in all the way was the culprit, but because of this site it was a very easy fix and saved me some good coin to be spent on my other toyz. Really sorry I didnt take any pics. Thanks To All

salimshah

My plea is out there for photos or marking on the motor ... There are members who are avid RC fans and maybe just maybe we can find an aftermarket motor.

Salim

powerslide

After cleaning the mode servo 2 times over a period of a year,I just replaced it. Ordered it from parts.com for 140 bucks. I fly rc and the motor is easy to find. The hard part is pressing the gear back to the shaft. Also have to find correct shaft length. The motor gets weak after a while even after the cleaning of the contacts.I cleaned the other servos and they still work great. Not as much force for them to move like the servo mode one.
2001 model RX

hogheaven

My mode servo on my 03 RX300 simply quit oscillating all together. I just finished cleaning the internals and re-assembling. I had to clean the grease off the face of the large gear in order for contact to be made. I left a little on, but very little. The only question I have is the rotational alignment of that large gear when re-assembly is made.?? There are no alignment marks of any kind that I can see. When the 2 halves are taken apart, the large gear, with the large arm attached to the outside, is free to rotate wherever it likes. Does it make any difference? It seems like it would, but I couldn't find any thread on the forum that addressed it?? Anyone know?