Raytheon 4000st

[Erwin Swart]

Just picked up my new boat with Raytheon st4000 autopilot.
Do hear the motor running when changing course though wheel doesn’t move.
At the same time I can fix the wheel with the lever so assume the belt is okay.

Also notice there is is screaming sound when manual steering.

Any ideas what can be wrong?

 

[jwilson]

There are a number of tiny plastic gearwheels inside the Mk II (grey case) ST4000 motor reduction drive gearbox. Sounds like one or more are worn out and slipping. Also one more larger one in the outer wheel-mount case that contains the belt. This one is located by a D on a metal shaft, and is easily replaceable when the D in the plastic wheel wears round. The inner ones in the motor gearbox are also replaceable, but not a trivial job. Buying a new gearbox unit that fits inside the motor case is easier.

See https://www.defender.com/pdf/261503_SERV.pdf

 

[Pete7]

Erwin, what colour is the wheel pilot, black or grey? The black ones are older, but have brass gears and worth saving. The later have plastic gears and can also be rebuilt.

Lots of videos on You Tube to show you what to expect when taking one apart.

 

[Erwin Swart]

Hi Pete, its the grey version.
will have a look to some videos and hope it can be fixed