hi all,
    I have been running the power hd 9150 mg servos on my larger gas planes - I noticed some of them were a bit noisy and when I opened one up I found there was next to no grease on the metal gears. So my question is what grease should I use to prevent eventual wear and gear slop? Is there anywhere I can get that white silicone based grease that you find in servo gears or is regular auto grease good enough?
any advice would be appreciated!    

I went for white lithium grease from an RC store (in the US), but I have read that similar stuff is available in stores selling electronics spares and related equipment (as this is applied on moving parts inside electronics equipments like the head mechanism of CD drives, casette players etc).

I use triflo grease, But since Servos are are not very high speed (like motor bearings), Cant we use white vaseline?

Vaseline is petroleum based, I think that is why it is not suggested for this purpose.

I see that vaseline is very similar to the grease used in Motors (Non -RC ones, like water pumps etc), so how does it matter, all are metal only 

Something about the the petroleum based ones fuming and causing stuff to fail.  Gotta dig up the exact details.  I do remember from day one that petroleum based greases are not good for our stuff.

I just read that they are not good for plastic gears/parts.

Thanks Anwar, thats a great tip! I will check out local electronics stores.
Vinay, my first instinct also was to just use vaseline but I resisted because its not normally used. But need to do some more research to find out the pros (if any) or cons.   
 

Try this little experiment, and you would get your answer why not to use vaseline apart from what has been said by others.
Take out the normal vaseline (it should be whitish looking gel form at room temp) in a small container and place it in sun. What do you see? The vaseline will melt into a colourless liquid.

Now suppose you have applied the same vaseline on the servo gears and the plane is out in the sun, where does all the melted vaseline go? Does that still remain adhereing to the parts it is supposed to lubricate? Actually after a few outings all the gears would have no lubrication at all.    

What about grease used for Big motor bearings / chains etc?

The grease commonly available in the electronic market is silicon grease and can be used safely with plastic as well as metal gears. It is very stable and does not change viscosity within the temperatures normally encountered.