Raymarine ST4000+

[sail4dale]

have a sick autohelm that stalls under a minor load.  checked the belt and adjusted the clutch to no avail.  Factory tech says it probably is the gear box or bearings in the motor.  ( the bearings race runs freely).  There is some ugly noised when the motor runs and stalls.  The serrated belt wheel is not slipping on the shaft.
Anyone of this great group of experts have a similar experience and if so what cures have you found rather than a factory R&R?

[rirvine]

Questions:

A.   Does the unit go through the random running of the motor AOK when it is powered on?

B.   Does the motor operate AOK if you take the drive belt off - does the motor work correctly under no load?

C.   Does the motor operate AOK if you do not engage the wheel drive clutch - similar test to #B?

Attempting to separate the problem into:

1.  Is it the drive motor binding in some way - bearings?

2.  Is it the belt drive binding in some way?


Ray