Rotavecta repair - removal of transducer "head"

[Kopite]

Hi,
Can anyone tell me how the head ( the part with the transducer PCB inside, number 4 on the image above ) is held into the long tube part ? I have the manuals but is silent on the subject. It does look like there is a groove on the tube ID that may interact with one of the O rings, but it's not clear.
I may need to remove mine to clean the bearings if I can't get it done in situ. ( mast is on the boat ), I expect to need a soldering iron to unsolder the two wires once I get it out.
Thanks on advance ,
Andrew

 

[Kopite]

Well, took a trip up the mast in the chair. Now I know the "pod" is indeed just held in by the o ring - or would be if it were there...mine was held in by some sealant. Now I'd like to get a new O ring, but Raymarine will only sell the o ring with a new sensor pod. I can head up the mast with a selection and try to find one that fits, but thought I'd ask in case someone knows the size. From measuring those on my speed transducer I'd guess it's probably metric.
BTW the issue with the transducer was simply cottonwood wrapped around the shaft near the bearing, inside the cap part..