Problem with Nero diff and servo.

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Arrma RC's
  1. Nero
Hello friends,
I have a Nero Big Rock and I am now replacing the rear diff servo for the 3rd time. The problem is, the servo can not disengage the diff locking ring enough to unlock the diff. It remains engaged just enough to barely catch this locking the diff. To get the ring to disengage far enough to unlock completely, I have to adjust the servo so that it over extends itself. Running the servo like this causes it to over work, it never relaxes, it bums and buzzes, creating heat and eventually failing. This is how it was adjusted from the factory and I've replaced it once already. This is my 3rd servo but it's just gonna keep going out like this.

I have checked and rechecked that all shims, washers, etc are in place. I bought a complete new diff assembly including the plastic case thinking maybe there was a defect somewhere, EVERYTHING except for the ring gear is new but I still have the same problem. This problem is only with the rear diff, the center and front diff adjust without problem.
Does anyone have any ideas? Remember that everything is brand new except the ring gear and I know how to adjust the diff brain for servo end points, I just can't get the servo to pull the locking ring back far enough to unlock the diff without hyper extending the end point.
Maybe something wrong with you're transmitter that the endpoints did not fit?
Normally I would expect that such kind of trouble occurs with the center diff, because this its the firs one which will controlled by the diff-brain -electronics.
I would try this way:
1. Reset the controller / transmitter.
2. check with a servo tester that the servo does work correctly.
Normally I expect no problems with that, you tell us thats new.
3. calibrate the diff-brain circuit board again, because the settings of the transmitter may different after reset..
If after all adjustments the same thing happens, it seams to me that something wrong with the diff-brain board.

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