Raymarine ST60 wind transducer refurb. problem, with photo

RichardS

RichardS

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Many of you will recognise this as a Raymarine wind MHU, partially dismantled:

IMG_6717.JPG


The disk-shaped wind direction circuit has failed so I have bought a new one to replace it.

Although the four bearings seem fine, I have bought 4 good quality stainless steel ones as I might as well replace the bearings at the same time. However, that does not look as easy as I had hoped as I can't see an obvious way to push out the old bearings.

All help gratefully received. :)

Richard
 
Hydrozoan said:
I’ve only ever seen instructions here for replacing the bearings on an early ST60, cylindrical housing type (which I have). Somebody on ebay offers a fitting service for the later type it seems, but I’ve no experience of that. https://www.ebay.co.uk/itm/Raymarin...-Vane-Bearings-O-Rings-windvane-/282945845287
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The construction does, indeed, appear to be different to the earlier version ..... but your eBay advert is interesting. The guy refers to the "white bearing carriers" but I cannot see how to get those out without destroying the housing that the carrier fits into.

It sounds from the advert as if it is possible to replace the bearings, and if these bearings were shot I'd be more brutal because I'd having nothing to lose. However, as the bearings are good, I'm being a little more circumspect.

Richard
 
Vegable said:
I can't really see where the old bearings are located. But tossing in an idea, using freezing fluid and fine nozzle from a plumbers supplier and a hot air gun with a small nozzle too. Any good?
Mike
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That's good advice and might well be a helpful aid to getting the bearing carriers/bearings out .... but, at the moment, I can't actually see where to apply the cold/heat and what to lever out. :ambivalence:

Richard
 
RichardS said:
I think you're right. I'll leave it to the combined wisdom of this forum and if nobody comes back with a procedure by next weekend I'll assume that it can't be done without specialist knowledge and/or tools. :ambivalence:

Richard
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I will be interested to see if you do get more information. I was given a set of bearings 2-3 years ago in Vigo. I mentioned an earlier issue with poor connections when chatting to another owner. He told me his unit was the same as mine,dived below and returned with some spare bearings left over from an earlier repair.

I've kept them in case I ever needed to work on the head but didn't ask about how to replace the bearing.

I could let you have the Raymarine Windvane Service Manual for that head. However, it does not mention bearing replacement. The only bearing reference is related to Top Pod (Part No. A28168)

It includes: Bearing, magnet assembly and O-ring seal

The diagram shows the bearing and magnet assembly as a single unit within the Top Pod.

It does look as if Raymarine only supply the complete unit. Doesn't mean that you can't replace the bearing, just that Raymarine don't see it as a profitable sale. At least they don't see a complete head unit as the only profitable option.
 
The bearings are housed in a split white plastic carrier that you should be able to see at the opposite ends to your photos. For the wind speed shaft you need to pull off the little black disc - it is a simple push fit on the shaft. Then you just push out the shaft, bearings and housing as a complete assembly - push from inside to out. They are only held in by a couple of thin o rings around the bearing carrier so should not need too much force - use a piece of wooden dowel or similar, they should push out by hand but may need a tap from a small hammer if not been moved for years. You should not need any heat or any other aid.

Once the bearing assembly is out you remove the o rings from around the white plastic and split it into two halves to get at the bearings.

Should be pretty easy, albeit a bit fiddly since it is all pretty small.
 
crisjones said:
The bearings are housed in a split white plastic carrier that you should be able to see at the opposite ends to your photos. For the wind speed shaft you need to pull off the little black disc - it is a simple push fit on the shaft. Then you just push out the shaft, bearings and housing as a complete assembly - push from inside to out. They are only held in by a couple of thin o rings around the bearing carrier so should not need too much force - use a piece of wooden dowel or similar, they should push out by hand but may need a tap from a small hammer if not been moved for years. You should not need any heat or any other aid.

Once the bearing assembly is out you remove the o rings from around the white plastic and split it into two halves to get at the bearings.

Should be pretty easy, albeit a bit fiddly since it is all pretty small.
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That's great Cris .... thanks.

I wondered where the 4 small O-rings included in the eBay refurb kit were supposed to go. I guessed that they were probably water-exclusion seals for the bearings but assumed that there must be something more than a hand push-fit holding the shaft assembly in place, particularly the lower wind speed one which would seem liable to simply dropping out. :ambivalence:

One question - does the little magnet have to be removed from the plastic claws on the wind vane shaft before I push the bearing holder out or is it better to just push against the magnet?

Richard
 
KAL said:
I used this thread as initial instructions for refurbishing my two ST50 wind transducers and hope it will be of use to you. I found the job interesting and relatively,simple to do.

http://www.ybw.com/forums/archive/index.php/t-442440.html
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Thanks KAL. I did look at that thread but the ST60 transducer looks very different to the ST50 so I decided not to risk it.

It's very surprising that there seems to have never been a thread about the ST60 so I'll post up some more photos for posterity later.

Richard
 
No need to remove the magnet, just push against it with a wooden dowel, you should not have to push hard enough to cause any damage to the magnet.

The push fit (and the small black disc) is the only thing holding the lower bearing assembly in place but obviously it is more than enough since I have never heard of one falling out!!
 
RichardS said:
Thanks KAL. I did look at that thread but the ST60 transducer looks very different to the ST50 so I decided not to risk it.

It's very surprising that there seems to have never been a thread about the ST60 so I'll post up some more photos for posterity later.

Richard
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I'm sure that a description with photographs would be very helpful - I'm very grateful indeed to those who did just that for replacement of bearings in the earlier ST50/60 unit. Good luck!
 
I'm beginning to understand why I have been unable to find a single strip-down walk-through for the updated ST60 wind MHU .... it's not exactly intuitive.

I've hit some problems but here is progress to date:

IMG_6727.JPG


The above photo shows the two halves of the central "egg" housing. The two parts simply unscrew by hand and there is an O-ring which provides weather sealing. I have removed the rubber cap which covers the wind direction magnet. It simply pulls off. On the wind speed side you can see the speed sensor disk, but more of that later.

IMG_6730.JPG


The above shows the other side of the central housing. The white thing is a split bearing carrier which needs to be pushed out. It comes out in the direction shown in the photo.

IMG_6731.JPG


Above is the first problem on the wind speed side. This sensor disk needs to come off and is a push on the end of the shaft according to Cris. However, it's a very thin plastic disk and it's on very tight such that I can feel it flexing when I grip the sides and try to pull it. I'm worried that if I pull any harder it will just shatter. What I really need is some way of pushing it out from the inside close to the shaft but that's a tall order.

I've tried just pulling the other metal end of the shaft out with the bearing housing from the other side in the hope that this would also force off the sensor disk but I can't get it to move in the vice.

IMG_6732.JPG


Now, this side is simple. I used the workshop vice with a socket over the bearing carrier end (13mm or something) and held a small 6mm bolt so it was pressing against the magnet and squeezed the whole assembly. The bearing carries just slides out easily. :)

IMG_6734.JPG


Slide off the two O-rings using a pin and slide a fingernail into the split in the carrier and it falls apart.

IMG_6736.JPG


But that leads to the next problem .... the bearings. Here you can see the ones I bought .... 3mm internal x 8mm external x 4mm wide. According to all the references I could find on the web, these are the correct bearings. However, Raymarine must have changed them for the new MHU.

I've measured the bearings on the shaft and they are 4mm internal x 8mm external x 3mm wide. A small difference but crucial. These are also a much more unusual size although they do have one stainless version at Simply Bearings so I'll have to see if they will exchange mine.

It's not really clear to me which end the bearings have to be pushed off and whether they will slide over the central section covered by the spring. I thought at first that it was a larger central collar but it is 4mm which is the same as the other larger sections of the shaft. The thinner sections which are located in the bearing carrier are 3mm but the bearings will have to go past 4mm whichever way you go. There is a 4mm collar hidden under the O-rings.

So, there we are. Two steps forward and one step back.

Any advice about the removal of that sensor disk or advice about the direction of pressing off the bearings would be most helpful. In the meantime, I'll see if I can change the bearings.

Richard
 
Last edited:
Hi Richard ... I've just removed the sensor disc by gripping the middle 'boss' with pliers and pulling off ( quite hard) but without the damage you would cause trying to lever the edges. Phil
 
PTB said:
Hi Richard ... I've just removed the sensor disc by gripping the middle 'boss' with pliers and pulling off ( quite hard) but without the damage you would cause trying to lever the edges. Phil
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Many thanks Phil. I haven't tried that because I don't really like gripping plastic with metal jaws but it sounds better than what I was trying to do.

I'll give it a go. :)

Richard
 
Exactly how I got the disk of the shaft when I stripped mine down, use a pair of pipe grips in preference to pliers and adjust so the jaws are parallel to the central boss when you grip it. Pliers are only going to grip on the very end because the jaws will not be parallel at the dia of the boss. It is only a push fit so should come off reasonably easily.

I didn't actually change the bearings on mine since they were in good condition, just a bit of extra lube needed, so can't help with removing them.
 
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