you need special grease that won't dissolve the plastic gears, I got mine in a RC store.

I used some allround grease used for bearings etc

Anyone with a solution for me?

Quote from Sorin FAUR :

Anyone with a solution for me?

I can see no reason for the unit would not work with the motors removed, but the motors are used to calibrate the unit whenever it is plugged in. This should be no reason why you could not calibrate it once the unit has finished its start up process.

In the end you have nothing to lose, You can always buy another one at a worst case scenario.

To ensure that you get the correct Grease, a decent RC shop able to supply the correct stuff for you.

If you are replacing one motor it will be just as easy to replace the other one when everything is removed.

Best of luck either way

Is there any" succefully changed motors? Can any1 explain what to do?

I think we need 10T gear for motors, and also if we change to mabuchi motor ex. 12v we shoul use 12V DC 2A Power supp. Shouldn't we?