ricco750

I have the infamous "gerbil noise" coming from my dash. After reading posts about people removing and servicing theirs, it seems that the noise often comes back. So...I figured I would just go ahead and get a new one, but I would like to make sure I'm getting the right one.

I'm pasting a link to MyLexParts, which shows a diagram of the hvac controls. Could someone verify which to get...#16, servo air mix, or #17, servo mode.

http://www.mylexparts.com/partlocato...layCatalogid=0

Thanks

salimshah

Dont forget #18 is there too.

The answer to your question is, you need the one that is bad. Which one is bad is hard to diagnose over the net.

Salim

ricco750

#18 is the recirc/fresh air servo. I just got in the car, key on engine off, and cycled the recirc servo, and it made what sounded like slight buzzing sound for a few seconds, then stopped. I did this several times with the same results.

I then cycled the mode switch, with similar results as the above.

I think I have narrowed it down to the air mix servo with these tests...any arguments with my logic?

melnme

Lexus part #87106-30371 is the one I replaced after total failure- sounded like a gerbil before it failed. It controls the blending of air through the vents including the front defogger. I wish I had your link sooner, I could have saved some $$. If you are looking at the servos from the passenger side, it is the servo that is most forward and easier to get at (IMO). Hope this helps.

salimshah

How about touching the servos one at a time to see which one is constantly hunting.

Salim

ricco750

Thanks, Mel...that's the kind of feedback I was looking for...I'm assuming you no longer have the "gerbil" after the R/R ?

melnme

All is quiet again, the gerbil is gone. I forgot how silent the car actually is.

JohnLX300

iTrader: (2)

I had the same problem, I thought the air servo was totally failed. After I pulled of the negative terminal for a minute, placed it back on the servo worked, gerbil sound, but the cleaning did work for me so I adjusted some spring, and never had a problem since.

salimshah

I still think that exact diagnosis is better than working with odds based on what others have had problem with. Most of the time the odds give you an edge, but if the test is fairly simple, one should perform it.

wish you luck.

Salim

ricco750

OK, I decided to just go ahead and remove and service both the air mix and the mode servos. The whole job took me about three hours. Removing that bottom servo was a pain because of access to screws, but determination and a variety of tool applications won out.

It looks like they were originally assembled with a white lithium grease. Because they are right next to the heater core pipes, I decided to use a synthetic grease on the gear surfaces. And on the contact wheel, I wiped it clean with alcohol, and then applied a thin layer of dielectric grease. Of course, I cleaned off the contact fingers as well, and bent them up maybe a sixteenth of an inch to give them more contact force.

Put it all back together, no more noise. And now I know much more about my climate control system! I'll post to this thread again if the noise returns, otherwise silence means I'm happy.

jkg

I had the same problem and ended up replacing both servos. cleaning them lasted only a day or so. The best way iMHO to tell which is a problem is to leave them in place and watch what happens when you fiddle with the controls. The air mix servo(#17 )responds to the righ thand **** and controls the level the air is coming from(footwell/dash/defrost). This is the one that was making the noise in my case. The mode servo(#17) is the lower, more difficult to get to of the 2. It responds to the left hand ****. turn it all the way clockwise or counterclockwise(HOT?COLD) and you can see it move. MIne was also bad-- didnt make noise but didn't respond to control and so didn't switch from hot to cold and back the way it should. Replaced both and now all is well!