Lubricant for Heater Control

[rasmuw]

I am in the process of rebuilding my heater control. The pivots of the cam pieces have a clear lubricant where they touch the body of the control panel, and the grooves in the cams have the same lubricant for the nubs of the moving arms. What is this? It has not hardened over the 18+ years of the car. Clear silicone does get hard after some time, and white lithium does as well. Could it be Vaseline? Something else?

[Vintage42]

... Clear silicone does get hard after some time, and white lithium does as well. Could it be Vaseline? ...

I did not know that clear silicone grease became hard. Vaseline is petroleum jelly, so it might have volatiles in it.

[rasmuw]

I did not know that clear silicone grease became hard. Vaseline is petroleum jelly, so it might have volatiles in it.

The Vaseline concerns me too, so I didn't use it. I think it is more accurate to say that the silicone dries out over time. Some of the lubricant on the surface of the white control plate seems somewhat dry, but on the moving surfaces it is still slippery. It seems safest to use the silicone and that's what I chose.

[jbrannon7]

It could be this, Krytox GPL 205. I got this free at work, I had no idea how $ it is. I would like to see a photo of the part, my heater temperature control has a bind and I am not sure where the bind is. https://www.amazon.com/DuPont-Krytox.../dp/B00NRPXDOK

Attachment 598954

[rasmuw]

Pictures can be found in this thread: https://www.bimmerforums.com/forum/s...ibution-Switch
The bind in the temperature control, the middle dial, is usually the blend door. Check the parked Z3 FAQ. I've found one other factor that makes the control bind just past noon--the right indicator light needs to be placed correctly or it will interfere with the cam that moves the lever arm.

[magnetchief]

Any synthetic grease that's safe for plastics will be fine.
There is a selection at your local auto parts store

Just make sure it states clearly suitable for plastics.


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[jbrannon7]

Pictures can be found in this thread: https://www.bimmerforums.com/forum/s...ibution-Switch
The bind in the temperature control, the middle dial, is usually the blend door. Check the parked Z3 FAQ. I've found one other factor that makes the control bind just past noon--the right indicator light needs to be placed correctly or it will interfere with the cam that moves the lever arm.

Thanks, my temp control, the middle knob, binds at about 11 o'clock. I can "massage it" for a few minutes and then the bind goes away, but comes back after the car is parked for a while. It feels like seal binding.

[Blacklane]

That is a seal binding. It's the deteriorated foam seal on the flapper door. Never force it, or you will break the knob. You can alleviate the problem by adjusting the Bowden cable so the door never fully closes.
There are lots of posts here in the subject.