ptbot

I removed the air mix servo as told in most of these posts. A youtube mechanic named "froggie" goes through and suggests a fix. Did it, fixed it! Not real difficult.

hypervish

Welcome to Club Lexus!

Glad to hear you got it fixed. I followed that video and it worked for me as well!

crazycarol

Can I just say how thankful I am for this forum?! My 99 RX300 with 218K miles on it had been making the "cd changing/scratching" sound for several years - and I didn't want to pay to have it investigated (minimum 5 hours labor)....fast forward to this year when I had no heat and came to this forum to seek help. Found out the 2 issues were connected! Followed the instructions on how to remove the Air Mix Servo (one must be very patient!!)
AND how to fix it - by cleaning sensors and redistributing the grease inside.
I am very happy to say it worked wonders and I have heat AND absolutely no
scratching sound! Yippee!! Plus I saved over $500 in labor costs and almost $200 for the part (which by the way is 87106-48020). Many Thanks!!

salimshah

Welcome to the CL. Please go through the stickies and I know the you have 218k miles on your RX but browse through the owners manual and you might discover some new things about your RX.

Post often and share. It is the contribution from members that makes this forum rich.

Salim

2therock

Wanted to say hanks to this sticky and add my notes.
I changed the air mix servo (hot/cold) in under an hour. I am a life long mechanic and have all the required tools.

2001 RX300 AWD. My Daughters Car.
Had to flex the aluminum fluid lines a tad to get at the rear screw.
Magnetic screwdriver tips required.
Extension mirror helps for seeing the rear screw.
No need to remove the CD player.

After removing the bad one I reconnected it and tried to operate it. No movement, no noise. The Daughter reported it sounded like a hamster was under the dash just before it went out.

The old one's worm gear was OK and not sliding back on the shaft. Everything looked fine.
I'm glad I did not pull it to see if I could repair it. I did this on a Silverado blend door actuator and it worked for a few weeks and back in I went.

Purchased the new one from eBay seller OEPARTS $123.99.

we are good to go. Forum Power saves my behind and wallet again.

sktn77a

iTrader: (2)

OK, this old guy is really getting confused with the terminology here. I've read EVERY (yes, EVERY) thread on this and find people using all kinds of different names for the two servos on the passenger side footwell. There are two servos - for the sake of argument, let's call them the upper and lower one. My understanding is that the upper one (closest to the gear shift tunnel) is controlled by the MODE control on the dash. And the lower one (located a little out from the from the gear shift tunnel) is controlled by the TEMP control on the dash. Correct so far? (I have no idea what an "air mix servo" is - sounds more like the temp servo but seems to be used as the mode servo in all the posts I've read).

I have the clicking noise coming from my dash when the MODE control is on FACE. If I change it to FEET, the clicking goes away. So I'm assuming its the MODE servo that needs to be replaced. My searches on the forum have shown multiple part numbers for this servo but the most common one appears to be 87106-30371. My question is: is this the correct part number for the MODE servo?

Thanks in advance,

salimshah

Mix servo controls the mix of heated and unheated air and is driven by thermostat (temp setting)

I did not use fresh air .. as there is recirculated air and chilled air from the evap coil].

Salim

sktn77a

iTrader: (2)

Thanks Salim.

Anybody know the correct part numbers?

maxSteel

This is what I have in my notes:
​
SERVO SUB-ASSY, DAMPER (FOR AIRMIX)
87106-48020

SERVO SUB-ASSY, DAMPER (FOR MODE)
87106-30371

Salim described the purpose of the air mix servo.

The mode servo determines which ducts the air will be directed to.

sktn77a

iTrader: (2)

OK, thanks. Not looking forward to squirming around under the dash..................!

LSBen

I found the youtube videos by "Froggy". I was always wondering what those strange noises were. Now I know after reading this post. When I have the time, i'll have to attempt this fix on my 04 RX330 awd 200k mi.

centerice

Thanks to all for this thread. I was able to fix my air mode servo using the videos and info provided. One note, I put my repaired air mode servo back in and it would move to only one position and freeze. After a lot of diagnostics and head scratching, figured the only thing I could of goofed up was repositioning the electric motor. I removed the servo, opened it up and reversed the motor in it's seat. After all was put back together, it works like a charm. Motor is DC so remember the lettering position on the motor when you pull it and avoid my mistake.

rosen71

Hi there,
After good few problem-solving cases with Air/mix servos, together with my friend we found the most frequent cause for not working properly.





The grease is gone, and when no lubrication of the tracks, they are also gone. It seems that it depends from the climate where the car is. As most of the cars we drive here a imported from Southern Italy, where the climate is warm, and no heater is used (or very rarely), the position of the potentiometer is changed very little, and that grinds the tracks.


I believe that this problem is a part of that
https://en.wikipedia.org/wiki/Planned_obsolescence

hsmac

does the contact plate require grease to function? something is wrong with my servo. i don't think it is the arm position because i hear something moving inside but sometimes the arm does not move, or it moves very slowly. i noticed the motor rod does not move without resistance, but maybe it's supposed to be this way? i put some thread locker on there and may have gotten some where the rod meets the motor body (which could explain why it's moving slowly?) the contact plate also has a tiny section where it is scratched through, but seeing as though the arm CAN move from one side to the other, just doesn't always do it or is slow (compared to the speed of the mode servo moving), i don't think it's the problem.

p.s. anyone know where we can get the motor by itself and what the specs/description would be?

hsmac

anyone? for some reason the rod on the malfunctioning motor is very stiff while the other one rotates freely. i switched motors between the servos and the stiff one isn't working well. since it was making the clicking sound before i fiddled with it i assume i damaged it somehow or maybe someone knows why it would be so resistant. anyone know where to get the motor itself? thanks.