Raymarine autopilot update

[John Langford]

Has anyone replaced the drive ring (the doughnut on the wheel itself) and motor on their 2000 era ST4000+ autopilot? The old one is black and the replacement unit is anodized aluminum I believe. I am interested to know if the connector to the back of the motor is the same (and wired the same) for both generations. I am getting some not healthy noises out of my drive ring and can see a need to replace it and the motor soon.

[Roc]

Hi John,
Did you open it up to see what may be causing the grinding?  Might be something you can fix.  I had a situation a few years ago where the ring just broke apart and a few of the little drive wheels inside fell on the cockpit floor.  I did get all the pieces, when upon inspection, I noticed the plastic posts where the drive wheels were mounted sheared right off.  Luckily, they sheared in such a way that I was able to drill out one side of the doughnut wheel, and thru-bolt the sheared posts, along with the drive wheels.  The posts were molded in one side of the doughnut wheel and the drive wheel bearings were screwed onto the posts.  It's been working good as new.  Easy fix with $3 worth of SS nuts and bolts 

[John Langford]

I was going to do that but a local boat electronics dealer and repair guy says that a high percentage of the "doughnuts" that he opens up are broken in the process and never work again. Since mine still works but makes loud distressing sounds when correcting course I have been reluctant to take the chance on destroying it before I sort out what my options are. This unit has been on the boat since 1999 and I am surprised that more folks haven't been faced with similar circumstances.

[Stu Jackson]

John,

This issue has been around since they started making 'em.  You are very fortunate that yours has lasted so long, no doubt due to the care you take with everything on your boat.

A search on "ST4000" provides tons of hits, many of which discuss the repair and refurbishment of this piece of gear.

One example:  http://c34.org/bbs/index.php/topic,8085.0.html

I also read this recently: (scroll to the top)

http://forums.catalina.sailboatowners.com/showthread.php?p=1227600&highlight=st4000

Good luck.

[Indian Falls]

I took my motor all apart last year, it was making that dry bearing noise every time it corrected course. 
Drove me nuts!
There really is nothing in the doughnut part that can be noisy, there' a belt and some rollers.
The motor comes apart quite easily from the end with the wire, unscrew it.  I pulled out the gear clusters, wiped off all the old dried grease and reassembled using some synthetic motorcycle engine oil.  (20-50)
It's noiseless now.

Just be careful not to loose any pieces and remember to get some of that oil on the motors sintered bearings too.

The doughnut pops over the nylon rollers so  work it careful when separating and putting back together.

Until my electronics bite the dust, I'll have this until I sell the boat with all probability.