Removing Raymarine ST4000+ from Edson Destroyer Wheel — Need Guidance

[testingthewaters91]

Hey all,

Solo sailor here working on my 1981 Hunter Cherubini 30. I'm trying to remove a Raymarine ST4000+ wheel pilot from my Edson Destroyer-style wheel, and I’ve hit a bit of a wall. I figured I'd post in case anyone else has done this dance before and can save me from breaking something expensive.

So far, I’ve removed a few of the obvious nuts and screws from the gray drive ring. But it looks like I’ve hit the point where I need to actually remove the wheel itself to fully slide the autopilot off. That’s where I’m stuck.

The center of the wheel hub has a circular metal cap—looks flush and has a little circle imprint in the middle. At first I thought I needed a special tool to poke in there, but after poking around online, I’m starting to think it’s just a decorative press-fit dust cap. Can anyone confirm?

If so, what’s the safest way to pry that cap off without damaging the stainless or surrounding material? I don’t want to scratch anything or deform the cap permanently.

Assuming I get that off, I’m guessing there’s a big nut underneath holding the wheel to the shaft. Anyone know what size that nut usually is? I’ve got a full socket set and an adjustable, just want to be prepared. Any issues with pulling the wheel off the taper? Should I hit it with penetrating oil beforehand?

Also curious if there's anything I need to be careful about when reinstalling later—like alignment with the drive unit or sensor. I know Raymarine units can be fussy about calibration.

Appreciate any insights. Trying to get the autopilot either fixed or removed entirely—right now it’s acting flaky and I suspect the clutch ring or internals are worn out.

Thanks in advance—cheers from the cockpit.

 

[Don S/V ILLusion]

Use a puller if you can’t wrestle it off. It just slides off but sometimes the key (slot) can accumulate a bit of corrosion making it difficult to slide. Nothing else holds the wheel on the shaft.Cant see any cap.

 

[Tally Ho]

It looks like the wheel shaft nut is missing already, so the wheel should just slide off the shaft. As Don said, it can take some muscle, wiggling, etc to get it off. Remember to put some grease on the shaft when you put it back on!

Also, you will need to disconnect the wire from the back of the wheel drive motor. It just unscrews, but it is a little fragile, so take it easy.

Greg

 

[JoeWhite]

As it is mentioned above. I used steering wheel puller with longer than normal arms, it is available from any auto parts store. Spray WD40 in the Crack to loosen the shaft.

 

[Ralph Johnstone]

I completely removed my ST4000 drive and replaced all of the belt bearings and bearing pins. Fun job during the winter in a heated workshop. The bearings were 3D printed by i3DGear Marine.

The center of the wheel hub has a circular metal cap—looks flush and has a little circle imprint in the middle.

This is the ass end of the shaft and the wheel should slide right off (if it was lubed during assembly). The aft end nut has already been removed. If not, heat the wheel hub with a propane torch and then pull. Variations of this will remove the wheel. As @Don S/V ILLusion noted, nothing else holds it on the shaft other than maybe a rusted key.

Assuming I get that off, I’m guessing there’s a big nut underneath holding the wheel to the shaft.

The nut which holds the wheel on the shaft has already been removed but hopefully not lost. It keeps the wheel on the shaft. Once you remove the corrosion from the shaft and lube it, the wheel will not stay on the shaft. This can be embarrassing when under way.

Any issues with pulling the wheel off the taper?

It's not a prop shaft. It's a straight keyed shaft with no taper.

I hope I'm dead wrong here, but please tell me you're not taking the drive head apart without the disassembly/assembly manual. I found it a little touchy for adjustment in some areas while working WITH the manual.

Good luck.

 

[testingthewaters91]

I completely removed my ST4000 drive and replaced all of the belt bearings and bearing pins. Fun job during the winter in a heated workshop. The bearings were 3D printed by i3DGear Marine.



This is the ass end of the shaft and the wheel should slide right off (if it was lubed during assembly). The aft end nut has already been removed. If not, heat the wheel hub with a propane torch and then pull. Variations of this will remove the wheel. As @Don S/V ILLusion noted, nothing else holds it on the shaft other than maybe a rusted key.



The nut which holds the wheel on the shaft has already been removed but hopefully not lost. It keeps the wheel on the shaft. Once you remove the corrosion from the shaft and lube it, the wheel will not stay on the shaft. This can be embarrassing when under way.



It's not a prop shaft. It's a straight keyed shaft with no taper.

I hope I'm dead wrong here, but please tell me you're not taking the drive head apart without the disassembly/assembly manual. I found it a little touchy for adjustment in some areas while working WITH the manual.

View attachment 233321​

Good luck.

Just to be clear, I have not removed any nuts yet. I'm not sure how people are gathering that the wheel shaft nut has already been removed.

Also, I'm just trying to replace the belt because it seemed old. I don't know about any other necessary or recommended maintenance.

 

[dlochner]

I'm not sure how people are gathering that the wheel shaft nut has already been removed.

Because the photo you posted does not show the nut.

Some shafts are tapered, some are not. Generally Edson uses a tapered shaft. From the photo, it appears the wheel is installed backwards with the skinny (tapered) part forced on first and the fat part last. That would account for the gap around the shaft in the photo. The only way that is going to come off is with a gear puller.

 

[kloudie1]

The wheelpilot drive should be "fixed" by drilling through the little wheel mounting screws and replacing the screw with a through bolt and washer on the outside. Typically, the plastic bushing support breaks and the wheels jam the drive once loose. While you are in replacing the belt, get that done as well.
Raymarine ST4000+ autopilot service & replacement... - YouTube
and:
Autohelm Raymarine st4000 wheel drive belt repair 001

 

[testingthewaters91]

At this point, I’m fairly certain this boat was assembled in reverse—every system just a little off, every fitting slightly nonstandard. And maybe that’s the hidden gift. There’s no better teacher than a boat that insists you unlearn and relearn everything, one seized part at a time. Still, it’s been more head-scratching than smooth sailing.

That said—sincere thanks to all who responded. I came here hoping to sort out a stubborn wheel pilot and instead received a masterclass in shaft mechanics, autopilot quirks, and what not to do with a Raymarine drive unit. This forum is like a chartplotter in unfamiliar waters—steadying and surprisingly generous.

As I move forward, a few questions linger:

– If the hub is truly frozen on, how far can I safely go with heat before risking damage to the shaft or surrounding hardware?

– Once the wheel is off, are there best practices for preserving alignment when reinstalling the drive ring? Should I be marking positions before removal?

– And if the belt swap goes smoothly, is clutch calibration still a likely variable—or something best left untouched if it's still engaging cleanly?

I’ll report back with the results—hopefully with the wheel off, the drive intact, and a little wisdom gained in the process.

—TestingTheWaters91

 

[Tally Ho]

Just to be clear, I have not removed any nuts yet. I'm not sure how people are gathering that the wheel shaft nut has already been removed.

Also, I'm just trying to replace the belt because it seemed old. I don't know about any other necessary or recommended maintenance.

Here is a photo of my wheel, still mounted on the pedestal. Note the large nut clearly visible on the wheel hub.

The shaft should stick out beyond the hub (you should be able to see the threads) and the nut holds the wheel on.

My shaft is a straight shaft, not tapered. But it was hard to get off the first time I removed it. I now grease it every time I remove the wheel.

Can you take a photo of the of the shaft behind the wheel (between the wheel and the pedestal)? See the shaft behind my wheel? Maybe someone put the wrong wheel on your boat or something.

Greg

 

[jssailem]

You can’t do anything with the AP Wheel pilot until you get the Edson wheel off. Let’s focus there.
Edson used a tapered and a straight shaft on their wheels. The tapered had a hub nut. Your wheel looks like a straight shaft in the image.

here is a picture from the Edson manual showing a center screw cover that appears to hold the wheel onto the shaft.

This one has a knurled knob hiding a nut. Your hub looks different.

I would send a photo to Edson support and ask the question.

 

[dlochner]

Given the age of the boat and the quirks in how it is put together, now might be good time to service the steering system, check the bearing, the chain, and the cable. The guts are accessed by removing the compass. Once the compass is removed, there are 4(?) SS bolts that can be a challenge to remove. Edson sells a rebuild kit. When reassembling, use Tef-Gel on all the SS bolts and screws.

Alignment is pretty straightforward. Decide which spoke will be the King spoke, the one centered when the rudder is centered and mark it. I use a piece of tape on the spoke. The cables have a section of chain connecting them, the chain should be centered over the sprocket. It may be necessary to loosen the cables at the quadrant to center the rudder and the chain. Check the orientation of the wheel to see if the King spoke is at TDC. Adjust the chain, if necessary, to center it over the sprocket. Take up the slack in the cables while maintaining the wheel and chain in the correct position.

Check the idler pulleys. The axles and the bearings can wear and can develop flat spots. Replace if worn. Check the chain for wear and fishhooks, replace if needed. Lubricate the chain with some motor oil.

The one mistake people make is not crossing the cables in the pedestal. The cables come off the sprocket and go to the other side of the pedestal before going to the idler pulleys.

Once you open up the pedestal, it will become clear how the system works.

 

[Tally Ho]

I think this is the end of the shaft….and I don’t see any sort of nut on it…. It should pull off.

 

[jssailem]

Yours maybe a friction fit. Perhaps with set screws holding it in place. I have not seen one of them.

 

[jssailem]

My thoughts is that would be a weak design for a sailboat steering. That said Edson has a lot of knowledge and they have experimented with different designs over the years. Call support. Show them the image.

 

[Tally Ho]

It could be tapered and someone smashed it on to the shaft.

based on this data sheet from Edson, the Hunter 30 used a tapered shaft…

https://edsonmarine.com/content/Sailboat%20DS/HUNTER%2030%20%28S-631-3%29%20D.pdf

It also shows a 5-spoke, 22” wheel. The photo is a 6-spoke….so, who knows if some PO changed it or if the Edson spec sheet is not accurate?

Best to call them.

 

[jssailem]

Best to call them.

 

[testingthewaters91]

I have requested information using their Contact Us form, as no phone number was on the website. Wish me luck in getting a response.

 

[JoeWhite]

I wonder if you have to pound it in more, then remove the key then pull out the wheel?
Here is how I strengthened the wheels inside the AP.

Wheel Auto Helm | Sail La Vie

mei1970.org

 

[Tally Ho]

I took some photos of my wheel and shaft this afternoon.

My wheel is held on with a large cap nut…


Once that is off, you can see the threads and keyway on the shaft. Mine is a straight shaft…and well greased, so it slides right off.


If I slide the wheel off the shaft, it looks a lot like @testingthewaters91 (TTW) photo…



When putting the wheel on the shaft (with the wheel drive attached to the spokes), you need to guide this pin (mounted on the pedestal), into the hole on the back of the wheel drive. Otherwise, the wheel won’t slide on the shaft completely (and may look a lot like the photo TTW posted.



Also, before removing the wheel and the drive, you will need to undo the wires leading into the wheel drive motor.



I normally remove the wheel from the pedestal, with the wheel pilot in place (just disconnect the drive wires) and then take the cap screws out of the drive ring to take it off the wheel spokes.

When you reinstall the drive ring, it will sort of “self-center“ on the wheel spokes…just keep all of the clamps loose at first, and then get all of the screws started…then you can tighten them.


Greg