Oh man, really bad flight problems. The lower blade was making a weird sound. Immediately i stopped flying it. I did the search to find the problem. Wouldn't u know, the lower blade's gear was missing a bunch of teeth, and skipping others!

So My quexstion is... Is that part replaceable? And if it is, how?
If i can get it replaced id put in the heat sink then, it seems nearly impossible!

Is this what your talking about ([link=http://www.greathobbies.com/products/productinfo.php?prod_id=EFLH1155]Drive Gear[/link])?

Actually no...he needs the Outershaft Main gear part # EFLH 1213

I've had evey piece of my Cx apart already a couple of times..if your not good at repairing stuff or if your not good with working with really small mechanics you may want to have someone else replace the gear for you cause there is a fair bit involved to change that gear which basically involves removing the entire shaft and rotor workings of your helicoptor which can have quite a few things that need to be removed first otherwise you will go nuts wondering why you cant get things apart not to mention you have to replace your gears and retaining collars back in just the right place lining them up with the flat parts of the shaft so your rotor shafts don't come loose and end up comming apart in flight it can also cause your helicopter not to even get off the ground if not done right. It definately is a replaceable part and it is a repair you can do if your comfortable with it but again if not have someone else do it for you it may save you some headache later.

I got it replaced and working thanks~