Disassemble ST4000 MK2 wheel unit

[Project_Mayhem]

I noticed the motor on my autopilot was a bit loose today. There were no obvious screws holding the two halves of the housing together. Are they held together by the same screws that are holding it to the wheel? Asking before losing a few dozen ball bearings in to the water.

On a side note, if anyone has some play between the peg on your pedestal and the hole in the wheel unit, a couple pieces of heatshrink worked very nicely. Hopefully no more clunk sound

 

[Tally Ho]

I did a video on overhauling my old RM wheel pilot several years ago….maybe this will help (sorry…it is a long one)

Greg

 

[kloudie1]

YouTube is your friend. Search on st4000 and you will get some video and see the insides.

 

[Tally Ho]

I just read your post a little closer…if you mean the 2 half’s of the drive wheel, they just snap together. No screws.

see my video about 1:42.

Greg

 

[Project_Mayhem]

I just read your post a little closer…if you mean the 2 half’s of the drive wheel, they just snap together. No screws.

see my video about 1:42.

Greg

Yep! That's what I was referring to. Thanks for the help!

 

[Calif. Ted]

The bearings are held in a very lightweight black plastic matrix, I pulled one apart to discover the plastic had broken and the bearings were loose. It was non-functional at that point anyway, made crunching sounds when turning the wheel.

 

[jssailem]

In 2021, I rebuilt my EV 100 Autopilot. It uses the 4000MK2 wheel assembly. I used the same Chinese electric Motor that Greg used. Bought it on Amazon. I first thought it was the motor. I learned that the failure was the drive ring. Here is my parts discovery.

EV-100 Autopilot 4000Mk2 Wheel Drive Repair

When it comes to selecting an autopilot, if your boat has a displacement weight less than 16,500 lbs, the Raymarine EV-100 is a likely option under consideration. It was the primary option when I explored my first AP. Now that I am 5 years into use with about 2000 nm usage I have had to do a...

forums.sailboatowners.com

 

[Project_Mayhem]

I haven't disassembled the unit yet but it worked great for 6+ hours of straight use yesterday

In 2021, I rebuilt my EV 100 Autopilot. It uses the 4000MK2 wheel assembly. I used the same Chinese electric Motor that Greg used. Bought it on Amazon. I first thought it was the motor. I learned that the failure was the drive ring. Here is my parts discovery.

EV-100 Autopilot 4000Mk2 Wheel Drive Repair

When it comes to selecting an autopilot, if your boat has a displacement weight less than 16,500 lbs, the Raymarine EV-100 is a likely option under consideration. It was the primary option when I explored my first AP. Now that I am 5 years into use with about 2000 nm usage I have had to do a...

forums.sailboatowners.com

There's some great info in this thread! I wonder if it's possible to use a wheel unit from another auto pilot that's more robust. If amperage and speed are too much for the drive unit, a resistor could be used.

 

[jssailem]

Good question. I spoke with an Autolhelm engineer in England. He said that Raymarine bought the company. They decided to "lighten the materials of the wheel." I asked if I could use the EV100 with an old Autohelm 4000 wheel. He thought it would be possible. Likely, the motor could be an issue. He could not encourage it as the conversation was being recorded.

With the EV100 there is a maximum 7amp continous drive current from the ACU.
This becomes a factor for the hydraulic version. The EV150 produces a maximum 12amp continous drive current from the ACU. This unit is used for their hydraulic power boat system.

 

[Project_Mayhem]

Good question. I spoke with an Autolhelm engineer in England. He said that Raymarine bought the company. They decided to "lighten the materials of the wheel." I asked if I could use the EV100 with an old Autohelm 4000 wheel. He thought it would be possible. Likely, the motor could be an issue. He could not encourage it as the conversation was being recorded.

With the EV100 there is a maximum 7amp continous drive current from the ACU.
This becomes a factor for the hydraulic version. The EV150 produces a maximum 12amp continous drive current from the ACU. This unit is used for their hydraulic power boat system.

This is useful info. I'm curious how well the system would work with a wheel unit from a different brand altogether. All this to save a few cents per unit

 

[jssailem]

The Raymarine wheel is expensive. If I had to replace it I would look at installing a linear drive unit.
I fortunately I found, via an online search, a replacement Drive wheel. They were wildly priced. They break do to moisture getting to the plastic. Now I remove my wheel and store it in the cabin when not on the boat for greater than 4 weeks. Easier to remove the wheel than unbolt the Wheel AP.