ST7002 Autopilot
While we were in the Amazon Delta last month our ST7002 autopilot quit working. The unit made a loud grating noise - it sounded like spinning gears which were not fully engaged. The fly in the ointment is that the unit started out life as an Autohelm 7000. We have replaced the control head, but the computer and the type 2 long linear drive unit are the original Autohelm components. We think that the unit was manufactured around 1991 - this is based on the motor label which indicates DATE 2/90.

I dismounted and opened up the linear drive unit. The inside of the linear drive unit had a large amount of black dust - it appeared to be brush carbon, but could have come from the black plastic gears. The drive belt (300 3M 12 469D) had some wear, but it appeared to be in serviceable condition. I disassembled and inspected the components. I connected a source of 12VDC to the motor - it ran fast and smooth. The resistance between the leads of the motor is .6 ohms (measured with a Fluke Model 23 Series II digital multimeterI). I connected the 12VDC source to the clutch coil and it had a strong magnetic field. The resistance of the clutch coil is 27.3 ohms. The clutch coil seems free to slide axially on its mounting pin. Both the small motor drive gear, and the large belt driven gear on the drive shaft seem to be serviceable. When I pull the tiller arm in and out, the planetary gear unit rotates freely. However, there is quite a radial wobble in the 4 planetary gears, which allows the clutch top / planetary gear housing to have a radial wobble.

I removed the circlip on the shaft end and pulled the steel clutch plate / plastic drive gear assembly. Both the shaft bushing and the plastic ring gear teeth on the clutch appear to be serviceable. I removed the roll pin securing the brass planetary gear base to the output shaft. The wobble in the planetary gears is as a result of excessive wear of the small drive gear which engages the 4 pinion gears. The planetary gears do not seem to be excessively worn.

I called the Raymarine Technical Department and spoke with Mark - he was quite helpful. He told me that the problem was that parts are not available for units built before 1989. The motor-side of the baseplate has a three box label with the following numbers: (upper two boxes) 2029 and 12V, (the lower box) 400004. There is a label on the FRACMO motor (serial 3666/366) with "DATE 2/90" - which indicates that if the motor was manufactured in February 1990, then this unit was built sometime after that date. Attached are 10 photos for ID purposes.

Mark told me to set up an account on this forum and post the information I had so that the folks in England can try to establish the date of manufacture for this unit. Then we can order the correct replacement parts. It is my understanding that there is a bronze gear replacement kit to upgrade the plastic gears. I would like to not only replace the broken components, but anything else you think we need to do. We are headed for the Panama Canal, and it is a long way across the South Pacific. I started out my career in the US Navy as an electronics technician, so with some guidance and the needed repair parts, we ought to be able to repair the unit.
Warm regards,
Tom Service
S/V Tiger Lilly
Spanish Waters, Curacao

Views: 700


Reply to This

Replies to This Discussion

I apologize for the delay, wanted to speak with our linear drive technician about your issue.

He explained that you will need planetary gear kit N021, this will come with the brass gears. He also suggested due to the age of the motor, he would recommend a new motor, and keep as a spare in case you get into any issues in the future, motor part number N002.

Are the part numbers the same for a type 1 linear drive?

I am the wrong guy to answer your question. I am just another boat owner who needed information from Raymarine.
You need to open a separate topic, and wait for the Raymarine technical wizzard (Underway - Raymarine, US) to answer you. It took them a couple of days to get back to me.
If you do take the same brass gear kit (N021), and you are in the Caribbean, Budget Marine carries these parts.
Tom Service
S/V Tiger Lilly
Spanish Waters, Curacao, N.A.

Rodney Kidd said:

Are the part numbers the same for a type 1 linear drive?

The brass gear kit is the same, N021.  The motor part number is different, for the Type 1 the part number is N001.

Reply to Discussion




  • Add Videos
  • View All


  • Add Photos
  • View All

Latest Activity

Profile IconRuss Frost, Arthur C, brian Roberge and 6 more joined Raymarine Technical Forum
47 minutes ago
Baard Johansen replied to Baard Johansen's discussion i60 Stopped Showing Wind Speed/Direction with e125 on v15.59
"I have a tech looking at it today. I don't know if the mast head unit attaches directly to the i60 or not. The unit was showing "0.0" kts, not dashes. Masthead and i60 are just over 1 year old."
1 hour ago
Joe Martin replied to Joe Martin's discussion C120 with RD418HD
"I will reconfirm my parts list when I get back to the boat. The better news is it looks like West Marine is trying to obtain an A92141D from Raymarine, which should allow me to more correctly connect these units."
9 hours ago
Moderator - Raymarine, US replied to Jim Rosbe's discussion E series data master problem
"Jim, The screen capture which I had requested was satisfied by IMG_4059.JPG.  This Device List shown indicates that there is not a functioning Ethernet connection between these MFDs. Q1.  Will send the e7 to Raymarine for…"
16 hours ago
Edd Schillay replied to Edd Schillay's discussion Powering an EV200 -- One 12V line or two?
"I'm not sure I understand what you mean by turning "off the power from the ACU". Could I just power the Seattle NG backbone and that would supply power to the ACU, p70, Sensor Core and future instruments? "
16 hours ago
Underway - Raymarine, US replied to Edd Schillay's discussion Powering an EV200 -- One 12V line or two?
"If your Seatalk NG backbone only consists of the autopilot system, the ACU-200 will provide power to the Seatalk NG backbone.  Once you add devices to the Seatalk NG backbone, like instruments displays you will need to turn off the power from…"
16 hours ago
Edd Schillay posted a discussion

Powering an EV200 -- One 12V line or two?

Greetings,I am curious about wiring up my new EV200, specifically the 12V power. How many 12V leads would I need? I saw a video on YouTube saying that the ACU needs a power wire and the SeaTalk system needs a power wire. Is that true, or does the power travel from the ACU200 through the SeaTalk and then to the other items (p70 and Sensor Core)? In other words, is it really as simple as this? …See More
16 hours ago
Moderator - Raymarine, US replied to Rob Franks's discussion Wind direction offset in e7 from ST-60 data
"Rob, I would recommend that you take a screen snapshot of the e7 and the ST60 and attach them to the discussion for further analysis.  The MFD and ST60 both be configured to display the same reference (true or apparent) when making such…"
16 hours ago
Gary Rubin replied to Gary Rubin's discussion NO FIX with accurate boat position; Case #6248
"Thanks for the reply. If I have a RS125, where can I find wiring diagrams for both Seatalk1 and NMEA0183 connections.  Since Raymarine no longer supports the Pathfinder system, warantee is the least of my worries. For Seatalk, I presume that…"
16 hours ago
David Downs replied to David Downs's discussion System losing unit settings. ST60 Tridata?
16 hours ago
Rob Franks replied to Rob Franks's discussion Wind direction offset in e7 from ST-60 data
"How can I tell which wind data is being output by the ST-60?  I don't see anything in the ST-60 wind instrument or it's manual that tells me any of that, or what it is outputting. This happens just sitting at the dock.  The…"
17 hours ago
Richard Cockrell posted a status
"Can I put My dragonfly 4 pro on the same battery as the outboard is on"
17 hours ago
Jim Rosbe replied to Jim Rosbe's discussion E series data master problem
"Here are screen shots of the c127 and e7, the "up" and "down", and that the all the devices are listed as active on the network. 1.  Will send the e7 to Raymarine for inspection/repair/replacement. 2.  How do…"
17 hours ago
Hartley Gardner posted a discussion

AIS 650 Update Failure

Hello, I downloaded the latest update for my AIS 650, including the latest version of ProAIS2.  I went through the instructions and executed the update program.  It reported success installing the new USB drivers, correctly identifies the older firmware rev in my 650, then tries to update the unit.  I repeatedly jumps back and forth between "changing AIS650 to update mode", with accompanying "beeps" from Windows (as if the unit was alternately visible and invisible to the operating system) then…See More
19 hours ago
Underway - Raymarine, US replied to Joe Martin's discussion C120 with RD418HD
"So just to confirm, the radar cable terminates in a Raynet Female connector, you state that you are using the A80160, that is a Raynet Female to a Female Seatalk HS connector.  You would need a male Raynet to connect to the radar cable.…"
21 hours ago
Underway - Raymarine, US replied to Baard Johansen's discussion i60 Stopped Showing Wind Speed/Direction with e125 on v15.59
"The software to the MFDs should not affect the i60 getting wind data directly from the masthead.  What is the i60 display reading?  --- dashes?  Have you checked the connections on the back of the i60 display?"
21 hours ago

© 2015   Created by Moderator - Raymarine, US.   Powered by

Badges  |  Report an Issue  |  Terms of Service